This message has been posted on their discord server yesterday, currently the app is being worked on and has no definitive ETA. We probably have to use other forks until that. I don’t know whether I can share the discord server’s link so not sharing that until a mod gives heads up.
put the repo back and do what? you can make a fork before they take it down and maintain it yourself if you can. tachiyomi needs external extensions to do it’s job, even if it won’t be maintained anymore. and idt neither tachiyomi forks or external extensions will be for long too.