[TorqueDog]

Unless you bought the Xbox for yourself before the kids came around, the Xbox is very likely Xbox One generation given that it and your oldest kid are the same age. In that case, their entire catalogue of games will still be usable on the new Xbox console (if they've got game discs then make sure you get a version with a disc drive).

They're getting toward that age where they're probably going to want to play the sort of games that simply aren't going to be on the Switch 2. But then again, if they aren't die-hard gamers then they might be totally fine with a Switch 2. And again, almost the same as the Xbox, the Switch 2 has near-complete backward compatibility with Switch 1 games (there's a few caveats), so either way, you won't lose out on the games you bought for the consoles.

So at risk of spoiling the surprise... ask them? Either bluntly or be sneaky about it and fish it out of them.