The Rec Center is starting to get a little squished (like it always does with a new game mode introduction). My idea is to divide the activity wing into two separate wings: One for PvP activities and one for PvE activities (i.e. Quest). Possibly more casual activities (disc golf, paddleball) towards the front of the PvP wing, with the Quests lined up in order of release. This would enable nearly infinite expansion opportunities while keeping the "hub world" layout of the Rec Center.
To further expand, the Merch Booth may be its own wing, with a much larger selection + a "featured" group (akin to what we have now in the Booth).