Your images are not deleted, they are sent back in "New" section, to uploaded, but not submitted yet, ones. So you have to resubmit it.
It's a new feature / mechanism on Adobe Stock. I also noticed it. Now, when you edit your image title / keywords, there is a pop-up screen asking to confirm metadata changes (you can cancel or confirm) after you click "Save". And there is also a link https://helpx.adobe.com/stock/contributor/help/submission-guidelines.html in that pop-up window.
The asset with changed metadata is returned with the same asset ID it was previously approved.
Funny, I had to remove only a punctuation mark, but, nevertheless, my approved asset was temporarily removed (i.e. sent back to "New"), then I resubmitted it and it appeared within seconds on my portfolio again.