I do the collaborative puzzle solving activity a lot, but prefer to set up some 15-20 puzzles I am going to review with Lucas Chess and share the screen on a Discord call rather than doing these on chess.com, precisely because of the cheating rule. So I for one, agree with Difster about the motivation for lifting the rule.
However, if chess.com lifts the cheating rule for puzzles then a lot of people will get to the highest points only to say "look ma, I'm da best". After all, cheating is about trying to get the recognition without the work.
I'd prefer to see a feature such as "Live Puzzles", where people can safely try to solve those as a community effort. I think e.g., it would be nice to see the arrows drawn by other people (in turns, so that they can't spam you while thinking or draw childish pictures), and a "voting for possible moves" feature where people can collectively vote for what they think is the best move, giving or taking points from a new ranking, rather than affecting the already established ones.
I believe that the rule on puzzles that getting outside help is not allowed should be removed.
First of all, I'm aware of quite a few streamers that do Puzzle Rush - Survival on stream that allow hints or even outright answers (not naming names) and I think that should be allowed. In every instance I've seen, it is because the streamer is genuinely trying to improve, not just a get a puzzle ratings boost.
Secondly, I know that there are chess coaches who use both Puzzle Rush and regular puzzles to train while they look on an give guidance.
Third and last point, unlike game ratings, one's puzzle rating doesn't affect their tournament eligibility or any other metric on the site outside of puzzles.
Caveat: Puzzle Battle, or any future tournament style play with puzzles should still retain cheating rules although it's highly impractical to cheat, since the board changes with each puzzle and time is very limited.