The first upgrades for the entire year will happen in July. There are 8 scheduled. 6 for August, and an additional 17 added onto that. My guess is at least half the 17 will be transfers (historically running about that) so maybe 22 upgrades (8+6+8=22) for July and August.

22 upgrades for the entire year so far isn't a "floodgate" but at least it's something!