I think it's safe to say that Mitsuki and Tsuboi will remain as Juniors. The only reason for Mitsuki to move to Senior rank next season is if he is shockingly not being considered for a JGP.
I read somewhere that Mitsuki was at the recent JGP selection event, and there is no reason for the federation to rush him to the senior ranks since it is so hard to survive on GPS on their own without any consistent quad unless they have high PCS like JB or AR. Tatsuya Tusboi even does not have 3A, so he is out of question for moving up to the senior.
Competition for the 7 available Men's JGP spots is going to be extremely tough. Similar to last season, I believe it's going to be "no 3A, no JGP". Difference is, there is now a lot more Japanese junior men attempting and/or with a relatively consistent 3A and several challenging quads. This could actually mean skaters with a great deal of talent and potential like Kazuki Hasegawa, Takeru Kataise (one of my favorites), Yuto Kishina (probably my current favorite junior), Tsuboi and even Koshiro will not get a JGP.
I agree. The last season originally Japan got 6 spots, but subsequently they got four extra from other countries, Korea released half of their spots which were earned by Cha, and a few others like Israel gave up some of their spots as well, so the total was ten spots. Japan initially named 5 skaters, Sumoto, Shimada, Miyake, Kishina & Yamakuma based on their past results, the result of the selection event and their capability of 3A (except Shimada as they believed his potential). Though Shun Sato got 3A, the quality of his other skills was not par with those five guys. Since Miyake and Yamakuma bombed at their first ones, Tsuboi who did not have 3A was sent to two events out of the sub list, and DID WELL with falls of 3A.
It would be nice if they can get extra spots like last year, but no guarantee.
Since this year Tsuyoshi Lucas Honda and Yuma Kagiyama have landed 3A at the local competitions, though we do not know how consistent they are, they are the part of the mix of this selection. Also Kao Miura who newly comes to the junior ranks can be a factor.
Based on the last year's result, both Mituski and Shun got semi-consistent 3A, Sena's and Taichio's were about 50%, Yuto's was about 20%, Tatsuya's was 0%, and Koshiro and Kazuki did not even attempt one.
Judging with all these facts and the last season's results, Mistuki is going to JGP, that is for sure, and probably Shun as well if his other elements got significant improvement like some twitter reports stated, also probably Sena will get a ticket. For the rest of the spots, it depends on how many extra spots they get, there is a tough competition among rest of the boys.
As for NHK, I am not surprised at the selection of Hioaki Sato at all since he is only one Japanese skater, besides those who earned their own spots, who got 3A and 4T. No, his 4T is not very consistent and surely others have attempted quads, but theirs were just attempts.
TBD is probably for Sota, Jun or Ryuju. I would be happy if any of them are selected for this. Sota is younger than others by 5 years or so, but currently he does not have 3A or 4T, and still nursing his injuries. I do not want him to push himself too much.
However, he needs to start practicing them soon if he likes to keep his Olympic dream alive. In order to be considered as one of serious contenders of the Olympic team, he needs to do well internationally during the previous season of it, which will be 2020-2021, that means he needs consistent 3A and at least one kind of quad, preferably two, by then. And the negative fact is that he did not have consistent 3A or 4T even before the injuries, and also he no longer has coach Nagakubo beside him, who was the sole reason that Sota moved to Nagoya. The rest of Howa club coaching team, Naruse, Kawaume and Hongo, all females, can they teach him big jumps?? Tatsuya, who is a member of the same club, is struggling with his 3A, and Ryuju never got the consistent 4T though they hired Takeahi Honda for Tatusya to teach 3A. So they can get some outside help.