Sorry for not being specific.
Yes, the current vibe is to put everything under .onion .
So if you used Namecoin you would have to go to reddit.bit.onion .
And if you used GNS you would have to go to reddit.gnu.onion .
And if you used MagicalNameSystem you would have to go to reddit.mns.onion .
The idea here is that keeping the .onion TLD is very rewarding for Tor, since we have already registered it with IETF and it's protected. So no one can steal it from us, and also other browsers know that it's special-purpose and they shouldn't leak it to the DNS servers. e.g. see:
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