It probably wouldn't. Pocket Camp has only a passing resemblance to any of the mainline Animal Crossing games from the standpoint of gameplay to the point of being extremely shallow. It's basically just a bunch of cobbled together assets from the previous games and shoved into a barely coherent mobile game. Though I do enjoy certain aspects of it, it's a game that is extremely hard to actually recommend, because it requires essentially being able to ignore every principle of logistical design and requires that you really enjoy what is just a small portion of the game (decorating your campsite, cabin, and RV) enough to put up with the grind of the rest of the game.Just mobile games honestly. Even Animal Crossing and Mario Kart. Rather Nintendo would just shift their to main games for switch. Would have tried Pocket Camp but fear it may mess up NH for me. :/
But it probably won't impact your playtime on New Horizons or any mainline Animal Crossing game.