AI have certainly been changing which joseki are popular and which aren't, but this isn't the same as increasing the amount of memorization in the game since joseki aren't new.

The AI favored lines are likely to get heavily entrenched. I wouldn't expect them to go further because they generally end when becomes better to play elsewhere. There are a few fighting joseki where this isn't the case, but AI doesn't seem to like them much, although there are a few exceptions.

> There are a few fighting joseki where this isn't the case, but AI doesn't seem to like them much

Do we know if those moves are actually weaker overall, or is there some other sort of selection bias at play?

I think some of the AI are trained by forcing them to play random moves every so often. That might bias them towards larger, more flexible openings where there are large regions of the board that make sense to play in rather than specific move sequences.

But if I were guessing, the AI probably doesn't like fighting joseki because it knows how the fight will end. AIs are much, much better than humans at working out who won a fight.