I would compare this new girl with the way Manbagi from Komi-san was introduced, but here being a little more serious with the romance part, i don't feel like this is a good idea, it just feels wrong to introduce another girl 200 chapters after establishing MC's loved person and his childhood friend, and it hasn't been that long since the reunion between MC and his crush. Who knows how this will develop but i don't feel this will be super great.