In my opinion, most people won't get confused by the 'old' interface being at a different subdomain, especially as Reddit did it themselves (apparently they had new.reddit.com
which hosted an older redesign than reddit.com
, like wtf!?? But somehow people understood that distinction, so this should be fine) Then again, I could be too much of a nerd and overestimating people :P (insert relevent xkcd here)
btw, does sopuli.xyz have the mlmym interface?
Someone replied to their post, with arguments and explanations I personally think are pretty well though out.