I mean, I don’t think so and if reincarnation was in the game, wouldn’t there be a tag for it? But besides that, I don’t think he fell in love because we’re apparently the reincarnation of the first female he fell for. Keep in mind that the whole reason why he started to have any feelings for the MC was because she helped him.
Let’s also not forget one of the bad endings if we don’t help him and we end up going into the tent Mc kind of gets shipped off somewhere. I think it’s that one shown or given genuine kindness or love. He’s easy to have feelings for others.
also, when the MC ask if he’s confused with someone else and that they just met, he makes it clear. No, he likes her for her he knows she is her. And wants to get to even know her more or something like that. Also, stating that he’s well aware they’re from two different worlds, but still can’t help himself. Which means if he really thought that we were the reincarnation of her I don’t think he would be saying he’s well aware of from two different worlds.