I know that he said all that but I think that due to hyosuke’s dislike of seshiro he might want to get away from his village and he might develop a positive relationship to the mc if it would help him get out of the village. Plus he always wants to be better than Koshiro it would be a perfect opportunity for him to prove that he might be better then Koshiro and with the time he then would spend he might develop an actual loyalty to the mc or a bit more friendly rivalry to Koshiro.
This would need to start before the mc and Koshiro left the village. The currently unavailable options like ‘wait for help’ in seshiro’s house could be an opportunity for hyosuke to try and become closer to being a kingsguard and to prove that he is stronger then Koshiro because what is a better show of strength than saving the king when even the kingsguard couldn’t or he could do it because he notices that seshiro is making a dumb decision.
tl:dr:Hyosuke could end up helping the mc in some currently not available decisions and might develop loyalty or even a friendship to the mc and maybe even get over some of the bad blood with Koshiro.
Sorry for making it so long I kinda got carried away while writing.
It would be unlikely but very interesting.