Yes, it's exactly this - they're short on space and couldn't fit everything while accommodating game traffic/gate access.
They also appear to have removed all the non-basketball banners from the interior of the building (1959 national champions banner, all the football and lax retired jerseys, etc., from the east end zone) and stashed them in three tractor trailers on Irving. They've removed most of the stuff in the memorabilia cases in the concourse near the Ernie Davis Room (though I hope they put them someplace safer than a tractor trailer). And I assume all the hoops decorations, including the new Wallace jersey, will get the same treatment on Monday.
It also looked like some weatherproofing was done where the last row of the upper deck meets the wall, but I didn't bother to climb up there and check.