Trending tabs are being deprecated due to low usage
GitHub could never quite decide whether they want to be a social network or not. The "Trending" page (which has been useless for a long time due to the ranking algorithm rewrite several years ago) is just one example of this indecision. The way users can vote on issues with "thumbs up", "heart", "rocket", and "fanfare" emojis (instead of simply "up" and "down") is another, and the ridiculous "achievements" on user pages is yet another. They've also added and removed the "Social Coding" label several times from their front page if memory serves correctly. It's like the whole company is having a neverending identity crisis.