Tomorrow I believe is when California will lift the ban on tv production. I'd imagine they have to spend some time prepping the house. Although I'd settle for a bare house. The theme doesn't matter. Just make it look like the old BB house, nothing flashy.
I wouldn't be surprised to see the old school schedule for BB. Back when it used to start around early-mid July. 2 months, 16 houseguests, 0 buybacks.