yes, I updated my asset pack pages with some new images and now they all have be deindexed, seems like there are quite a few support cases about the same thing. But I think I may have been delisted before I did an update tbh, probably around 1st May, as you mentioned.
I also published a new asset pack in this timeframe, and it’s not indexed either. Never had this issue before
My assets : https://sebbyspoons.itch.io/