All I hope is option to keep old forum layout or switch between old and new forum at will when this new one will go live. Because at first glance new layout is not that impressive imo.
I already said that the current theme won't be the final one and that there are probably going to be a few to change to. You can always request the change if that is not the case.
That's most likely what will happen, on a platform like transifex(which is used by Bitcoin Core as well).
Transifex was the first to come to mind as well.