"The end of 立ち読み (Tachiyomi) is the beginning of みほん (Mihon)"
Credit to LinkCable, the icon designer, for this poetic quote.
What's New?
Well, nothing, except you now you need Android 8+ to install...
The devs just said fuckit afterwards, as you do when you get a lawsuit saying your about to be so far in debt because of your side project that your whole life will be turned up side down.
Kakao (or whatever they're called) were going after everyone involved, so Tachiyomi has been deprecated, one of the devs forked it and will continue development.
A long time Tachiyomi developer made the commits making branding changes to Mihon, so they might work together. But as they didn't fork TachiyomiSY, its dev might continue work on it too.