It doesn't usually matter if you're using an RTX 1060 or a 4090, your render quality will generally be the same - the main difference is the rendering speed. Granted, having more raw rendering horsepower available may lead to an increase in model polygon detail, and thus some artists will generate higher quality stuff as a result, but I don't think it's going to be a real danger in the lifetime of a game. The best thing an artist can do (generally) is not muck-up the appearances of characters between updates, and save any re-render work for later.