I just opened a ticket for this: https://trac.torproject.org/projects/tor/ticket/8940

Right now the way to check for the current TBB version is by loading https://check.torproject.org/RecommendedTBBVersions.

It would be really helpful if there were a way to check the current version of TBB from a URL at https://www.torproject.org/. The main website has a .onion address, and all of the Tor mirrors listed at https://www.torproject.org/getinvolved/mirrors.html.en are mirrors of the main site, not check.

So if you want to only use the hidden service or only use a mirror (because *.torproject.org is blocked on your network), there's no way to easily know the current recommended version.

-- Micah Lee @micahflee