Modern and original versions of Chan and Seon According to the answer to this question there is a clear distinction between the traditional Zen practised in Japan until 19th century and its modern version invented by Suzuki. Is there such a clear distinction within Korean Seon and Chinese Chan? If not, which version of Zen do they correspond to?
Korean Seon and Chinese Chan both have distinctive styles and practices.
Here is a detailed study of Korean Seon that will be selectively quoted to draw conclusions about differences between the two and zen in Japan.
http://www.acmuller.net/articles/ogahae-oxford.html


  "...Thus, the well-ingrained custom of interpreting Korean Seon based
  on the models of Japanese Zen or Chinese Chan has also changed little
  over time, with Korean Seon regularly being seen through the lens of
  caricaturized takes of Tang-Song Chan with its radical non-scriptural
  tendencies and focus on encounter dialog, or a Japanese Sōtō/Rinzai
  model where textual studies are largely limited to the Shōbōgenzō and
  Zen poetry, and where meditative practices consist of either
  shikan-taza ("just sitting") or a graduated series of hundreds of
  kōans—and perhaps some sort of cultural admixture with the martial or
  fine arts. While Chinese Chan and Japanese Zen do have certain
  fundamental features in common with Korean Seon, the Korean tradition
  is in significant ways unlike the "meditation schools" of its two
  neighboring cultures. One of the more interesting distinctive aspects
  of Korean Seon, especially as compared with Japan Zen, is the
  character of its core literature.... And while it is true that we can
  also see in the sermons and private teaching records of many Seon
  masters through the Goryeo and Joseon periods the typical shouting,
  striking, and exhortation toward investigation of the hwadu that one
  would associate with classical Chan, there is at the same time a
  substantial amount of attention paid to scriptural study, recitation,
  and exegesis. Nonetheless, this study and exegesis is of a different
  character than the doctrinal work carried out during the in China and
  Korea during the Tang and Silla periods in that it has a distinct
  "Chan" orientation to it both in literary style and in the choice of
  topic texts."


So the above citations begin to outline the differences between Zen, Chan and Seon.
The question is did these different traditions radically change at a certain point in history like Zen in Japan under Suzuki.


  The Diamond Sutra is cited everywhere in the Seon teaching records of
  the Goryeo. Beyond its distinctive thematic orientations, the extent
  of its influence in Korea also has to do with its central role in the
  myth of the creation of the Platform Sutra, the story of which
  provides the source for the very name of the Jogye school.2 The
  Diamond Sutra also has its own special thematic affinity with Chan
  practice, as it is seen throughout the Mahāyāna schools of East Asia
  as the locus classicus of what is arguably the most fundamental
  teaching/practice of Chan: "non-abiding" (K. muju;Ch. wuzhu).


Seon for the most parts goes through fewer changes then either of its "parents." Now Gihwa enters the scene after centuries of decline in Seon in Korea and tends to revitalize and refocus Seon. Here is a little of his biography.

Gihwa (1376-1433)


  The lifetime of Gihwa (also known by the monastic name Hamheo
  Deuktong) fell in the midst of one of the most dynamic periods of
  social, political and religious upheaval on the Korean peninsula. The
  Goryeo regime, which had endured for over four centuries, but had
  become corrupt in its latter period, was on the verge of collapse, and
  as the leading Buddhist figure of his generation, many of the episodes
  in Gihwa's career had to do with his dealings with the epochal events
  of this juncture in history.5 Gihwa addressed in his writings a wide
  variety of Buddhist and non-Buddhist religious themes, but one of his
  favorite topics was the renewal of Jinul's argument for the
  essence-function connection of Seon and Gyo, which he addresses
  primarily within the context of the Oga hae. Besides this commentary
  on the Diamond Sutra, Gihwa also wrote the major Korean commentary to
  the Sutra of Perfect Enlightenment,6 a commentary on Xuanjue's Yongjia
  ji7 and an essay on the intrinsic unity of the "three teachings" of
  Buddhism, Confucianism and Daoism that is considered to be a landmark
  work in Korean intellectual history, entitled Hyeonjeong
  non(Manifesting the Correct). He also wrote a separate essay on the
  theme of the Diamond Sutra, entitled Geumgang banyabaramilgyeong yun
  gwan ("The Penetrating Thread of the Diamond Sutra"), as well as a
  number of shorter essays and versified works on various doctrinal and
  meditation-related topics.


So Gihwa did revive some of the traditional methods and warned about the dangers of extremists within Seon


  Gihwa should be seen as the major reviver of Jinul's argument against
  exclusivist positions taken by certain members of the meditative,
  mind-to-mind transmission oriented "Seon" school as opposed to the
  text-oriented, doctrinal stance of Gyo. While Gihwa was a Seon monk
  with a strong meditation-oriented perspective to religious
  cultivation, at the same time he also felt that the denigration of Gyo
  study methods by Seon extremists was unnecessary, and even harmful. We
  can see Gihwa's interest in the re-valorization of scriptural study
  both in direct prose addressing the issue, as well as in the mere fact
  of his extensive exegetical work.


So there may be others who revitalized Seon, but in many ways the traditional practices and texts of Seon remained unchanged over a long time. Of all 3 Seon, Zen and Chan, the Korean practice seems the most like a mono culture with a tendency to remaining close to traditions.

Cited from: The Oga hae seorui (Commentaries of Five Masters on the Diamond Sutra) http://www.acmuller.net/articles/ogahae-oxford.html#ixzz3CuhRVrTv