They aren't deleted you'll get them back.
don't worry, ppl whose acc were made in 2014 and 2015, as in earlier years, slowly got their reads back.
Currently 2019 users are getting it back and it has started for 2020 users too.
https://www.mangago.me/home/people/65330/home/
https://www.mangago.me/home/people/7934/home/
https://www.mangago.me/home/people/12004/home/
so yeahh it'll take quite some time but you'll get them back.
also once they're back, in case you're looking for ways to save them perhaps in an excel file, I've made a tutorial on how to do it easily and quickly rather than having to enter everything manually one by one, so if you'd like, you can check it out.
https://docs.google.com/document/d/14Drj0CviUhrAmZlU-DC-AtxGFQoH1_PYQ81b2Vzu82w/edit?tab=t.0

hey, so i just logged in on my account for after idk a month? and there are times that i havent logged in for a longer amount of time but this time something happened. every manga/hua/hwa that i've ever read just completely vanished. the stuffs that i added on my want/reading/already read lists are gone. i can still see my topics but all of those r gone. ive had 700+ in total on my lists since i was reading that much but i got unto i slump, and i come to this. last time i logged in, i still had my lists. is anyone in this situation? i just cant believe this since ive been reading since 2020.