Is there a consensus on whether amber can seal in air bubbles for millions of years? I read about deriving the oxygen content in the atmosphere in the Cretaceous by analyzing the air trapped in bubbles in amber from that period, but I have also found papers disputing the study's methods and showing that air isn't actually trapped in the bubbles because it's capable of diffusing through the amber (the amber isn't a perfect sealant), and thus the air found in that amber isn't necessarily as ancient as the amber itself.

My problem is is that almost all the relevant papers are from the late 80's; all those I've found are pro- or con-, I don't have the background to tell who is right, I haven't found a source that describes an actual consensus the field would have come to since then, and I see the claim about the original study showing what oxygen levels were in the Cretaceous cited in various places, but I find it hard to tell if it's because the objections were dismissed or if it's because it's a zombie claim.

Some sources:


What seems like the first paper to make the claim: 
Gas bubbles in fossil amber as possible indicators of the major gas composition of ancient air
This source seems to be more recent and find the same conclusions but it's hard to tell (looks like at least one person is the same as the 1988 source):
Air Bubbles, Amber, and Dinosaurs - USGS
The main disagreement:
Is the air in amber ancient?
Some back-and-forth:  


Google Scholar: "is the air in amber ancient"
The relative contribution of adsorption to the overall sorption and transport of small molecules in amber

An unrelated recent paper that comes to a different conclusion on Cretaceous air content (based on amber as well but carbon isotope analysis thereof):
Stable carbon isotopes of C3 plant resins and ambers record changes in atmospheric oxygen since the Triassic


Does anyone know if a consensus was arrived at on this question, and/or if one side is clearly more right than the other?
There is at least a fair degree of consensus (there will always be naysayers) that the results that were performed back in the 80s and 90s by Berner and Landis were false positives that could not be confirmed by further investigations. A good historical account of this can be found for instance in Nick Lane's book "Oxygen" (first published in 2002). Quoting from this book: 


  The overall consensus, which has now persisted for more than a decade,
  was that the air trapped in amber could not have been ancient [...]


That "could not have been" has an air of finality about it, and you can probably take this book's word as accurate. However, all of the amber in the world has not been examined, so I would say chances may be slim but not none that some will be found containing traces of an ancient atmosphere. Probably part on the answer depends on how old the amber is, and how it was preserved. A very different question is whether gases in the amber can be regarded as representative of the atmosphere of origin, or useful. Perhaps reactions with the amber (oxidation) during burial have altered it beyond recognition.