Well, to some extent, some of these assignments, especially GP, are going to be determined by WS and SB.
Heading into Jr Worlds, Worlds and WTT as the only events left for skaters to improve, the only two US men on the SB Top 24 are Ilia (3) and Camden (19). Presumably, if Jason skates at Worlds like he did at Nats, he'll join the other two on that list.
It's conceivable, though probably not all that realistic, that either Yampolsky and/or Broussard could edge into the SB Top 24 at Jr Worlds, but right now the only Junior man in the SB Top 24 is Kataise, who is sitting at #21, and there are plenty of men within 15 points or so of him that could surpass him at Worlds (Egadze, Kvitelashvili, Nordeback, Jin, Orzel, Mihhail Selevko, Shmuratko).
WS Top 24 we have Ilia (8), Nathan (10), Vincent (16), Camden (17), Jason (18), and Jimmy (24). Jimmy could remain in the WS Top 24 once the 2020-21 season results are dropped and the 2021-22 season results are reduced to 70%, but I haven't sat down and done the math recently.
It seems pretty certain that Ilia and Camden will get 2 GP assignments, and I'd be surprised if Jason doesn't also earn 2 on Worlds placement alone.
I'd guess Jimmy is likely to get 2 GP assignments (he's at 33 on the SB list), but it's certainly not guaranteed. On the SB list, Maxim is currently 28 and Liam 32. I'd guess they'll each get 1 assignment on the initial go-round; same with Andrew if he can skate as well as he did at Nats. And if one or both of Lucas & Robert medal at Jr Worlds, they'll probably get at least 1 GP assignment, possibly 2 (which is what happened for the 3 Jr World medalists from last season).
The USFS tends to send the skaters with GP assignments out to at least 1 Challenger prior to the GP season, sometimes 2, as a season opener, so if Jimmy gets 2 GPs, he'll most definitely get a 3rd international earlier in the fall.
I can't say, based on the current SB or WS, that Jimmy is undeserving of any assignments he gets next season. It's not as though the rest of the men in the World have been tearing it up and leaving him in the dust, score-wise. His inconsistency is aggravating AF, but goodness, the same can be said of almost every single man competing these days.