If they did a better job of cloning it than Sony did, sure! Could be fun to see some obscure characters from Microsoft’s past. Maybe Stubbs the zombie, or some piñata animals, maybe some grabbed by the ghoulies characters. Could be fun as long as they actually clone smash bros and don’t try to be too different like all stars.
They would have to make a buch better clone than Sony did if they wanted it not to fail.