It's been already announced that the last run happened and "everything should be back up". So you can pretty much pack your stuff and start adding titles again.
I understand how annoying it must be, though. I had 300+ on my currently reading list. The rest was either completed or on my TBR, but still a shit ton of titles lost.
As far as I know your lists will only come back if it's rated or tagged in the first place , and some will probably appear in your already read but it'll be mixed up , like ur stories from reading and want to read will appear in already read
And btw adding stories to your lists doesn't affect it if it comes back eventually so dw abt that
Atp just try to manually fix your list little by little and you'll eventually get back everything by yourself even if it isn't perfect

i actually can’t wait anymore, ik they said they lost everyone list, i keep being patient despite that and rely on my last notifications to read what i have left but now my notifications are expiring and atp i started readding shit idc anymore