I always was under the impression that his strength was in "packaging" skaters who were already had the jumps. I don't mean to ruffle feathers here, but no way would Timothy Goebel (2001-2003) and Evan Lysacek (2005-2010) had the success they had if they hadn't gone to Frank Carroll. You could also make a similar argument about Denis Ten.
And this is why Frank seems a kinda odd choice for Jason. Jason is already very well packaged... I don't know what Frank can really do in that department short of a complete teardown and rebuild... which is not needed. Really the only part of Jason's packaging that needs work is his costuming... and I don't now how much Frank is involved in that beyond saying no to things he does not like (I know he has vetoed stuff for Gracie that was already made and assumingly paid for more than once - so he can't be that involved in the process I would think). Really he could get better costuming with Skype and no travel.
I don't think Jason is thinking of coach hoping, but I don't think Frank would be a good contender for a permanent switch both because he is not who Jason needs, but also FRANK WANTS TO RETIRE... and I think people should be allowed to retire. Sometimes I feel like people like Frank need to be reminded that they want to retire.
Honestly, I think the only coaching change before 2018 that would be worth even looking at for Jason would be Brian Orser and The Cricket Club. I am not sure how much more other coaches can really do for him... but training with Yuzu and Javi would be priceless. Especially Hanyu, who seems to think highly of Jason or at least have a soft spot for him... I think he would actually welcome Jason rather eagerly and asking to do side by side quads on a daily basis till he got his way.
I think Tavi does bring something interesting up with the 3A. While I don't think Frank has ever been seen as a quad guru, he does seem to be strong with the 3A. So maybe a 3A boot camp with Frank makes sense. TSL did say that some nice 3As have been spotted out there. Kori has always wanted to make use of other coaches as well, so maybe Frank is just one of the few that is ok with that approach.
I have another theory about why it could be useful though. Maybe it was time to light Jason's competitive fire again and get him training somewhere where he was not king of the hill. Let's be honest, Jason kinda out classes everyone at 7k... an argument (please note I am not making this argument, just acknowledging it from an academic perspective) could be made that he out classes everyone at World Arena even. This could be psychologically about training in an environment with skaters that in some ways outrank him... or at least skating with their legacy. It is often said that training with top skaters really helps, and maybe this is part of what this is about. To take him out of his comfort zone, to remind him of what he still can achieve and fire him up. Skating with Gracie for Frank is a different power dynamic that he is used to, and could be beneficial.
Really though the it likely is just that he wanted to have some fun by the ocean with the Gold sisters while training. Nothing wrong with that, who would not have some interest in working in a beautiful but different location with childhood friends? It just seems so normal that it seems odd to not have mentioned it.
Also... hasn't he worked with Frank peripherally before? His wiki has had Lake Arrowhead as a former training location for ages. I think this was where he went/what he did to work on his 2A way way long ago...
and yes karne, the idea of Josh coaching Jason is adorable.