@ak2508 No. Competition's don't work like that. Tatara and Chinatsu got A rank as a pair. If they break that pair, the rank is lost. Even if Gaju pairs up with Chinatsu he can't automatically enter Sendai Grand Prix as an A-ranked pair, they have to start from the beginning of the dance season. Obviously it's easier for highly skilled dancers, that have formed new pairs, to climb up the ranks but it still takes time due to the scheduling of the competition circuit. .
Plus, with the intense emotional development Tatara and Chinatsu went through, there's no way this pair are going to break up. Pretty sure Chinatsu is the endgame partner and main female lead. Despite being the last one to be introduced she has the most screen time out of all the other girls and character development on the level of Tatara. Plus, we know so much about her outside of Tatara. Not easily replaced. That was a bond forged in the fires of competition hell. They're meant to mirror Sengoku and Chizuru.