You get on recent, if staff rolled a 3 or less on their dice. But sometimes they use D20 instead of D6.
Kidding aside, it is said, that staff has to approve a major update to count as "major update" or at least count as reason for getting bumped on recent again.
New & Popular is the same as Popular, but the emphasis is even more on "newness". I do not even know, if they use date from the recent list, or the publishing date. It would make sense to use the publishing date because of fairness.
They should overhaul how this works. I perceive it unfair to the developers that update their games without having major update devlogs.