I heard personal banks are equally effected, as well (I haven’t experienced it, yet) and 8 days ago, in an unrelated thread, I did share some items I still have in my personal bank, as a log source that I do have said items (not that Blizz accepts screenshots, but I digress), in my personal bank for memories:
https://us.forums.blizzard.com/en/wow/t/what-old-school-items-are-you-still-holding-onto/1915860/14
And, I just ask those to remain and everything else I had could be dumped.