SSIA I guess.
New sites on Tiddlyhost will be created with TW 5.2.0 by default.
If you want to try out some of those cool new features, go crazy at https://tiddlyhost.com/ 
-Simon
Ps, if you want to upgrade your existing Tiddlyhost site to 5.2.0, https://github.com/simonbaird/tiddlyhost/wiki/FAQ#how-can-i-upgrade-my-site-to-a-newer-version-of-tiddlywiki is a rough guide on how to do it.
Pps, FYI there was some extra work needed to get Tiddlyhost to support the new JSON formatted tiddler store. Thanks very much @saqimtiaz and @Jermolene for the help with getting that working and tested well in advance. (See https://github.com/simonbaird/tiddlyhost/issues/161 if you’re interested.)
Ppps, congrats on the great release, and great work everyone who contributed! Zarro boogs…?