Yes. Tachiyomi has removed all extensions from the app. Forks like TachiJ2K are affected as well. However, you can still download and use the existing extensions. They've been backed up to some external repos. Just choose the new repos as the extension source and you're good to go. But as they're not getting fixes and such anymore, those existing extensions will only continue to work until they don't anymore. After that, idk, maybe some new extensions will be developed by someone else, or you'll just have to bring your own content.