Would it though? It would probably sell pretty well to people that hang out in gaming forums. But, does that average Switch owner really care about playing that game? How about the average Fallout fan... do they want to rebuy a game they finished years ago? Do they even own a Switch? Certainly some of them would buy it. But, how many, really?
New Vegas in particular, would, at least to the point where they could get a return on their investment. Considering that it hasn't been yet re-released on the current gen consoles, it'd for sure attract new customers (the power of exclusivity), especially if it wouldn't be one off.