It sure seems that way. I've really noticed it this year because the past few years, I used BetJam and they generally didn't offer NCAAB totals overnight. I'd guess that at least 75 percent of the overs that I've bet overnight this year have nudged up at some point before game time. It seems like most of them peak sometime during the afternoon, with many trending down at gametime. However some keep going, like CO/AZ last night (the books are lucky that CO stopped fouling, that one was looking like a big middle).