Hi! English is not my native language so I'm not really sure if I correctly understood you mean by »new forum's interface« – as far as I can see the
interface is exactly the same as before (minus the tagging). Obviously the
layout or
skin has changed. But that's temporary and
not the final look. This has to do with the fact that the forum software has been updated.
But maybe you are experiencing problems with the upgraded software. IMHO it is rather obvious why software (fixed security issues, improved features, …) is updated from time to time and as far as I know the update on latex-community.org was long overdue.
I'm sure our admin Stefan will add a few insights!
Best