In MA, the process was people placing their *own* names in the ring for consideration to become a delegate, by stating the campaign that they wanted to be affiliated. Then, a delegates committee in the MA GOP determined the delegates from that list. A priori, each delegate candidate knows full well that there are lots of strings attached, and they'd have to fork out about $5000 to pay their way for travel, hotel, food.
The other common mechanism is, instead of a state GOP committee making the choices, holding a caucus where those wanting to go would meet up, each given a few minutes to speak, and then voted on by the R attendees.
So, this is why this whole thing is likely choreographed. For reasons apparently for now unknown. Put Barron in the news for about 2-3 news cycles, if nothing else.