Yes, you are right. I mean, it is Helix Native. Not “HX Stomp Native”. So I am pretty sure it should be able to do more.
Yes, the Amp sims on the Helix should be better than the ones from Boss, from what I understand. Boss also just released a Hardware just for Amp Sims (the Boss IR-200).
I guess they would rather have you buy both the IR-200 and the GT-1000, so I don’t see them updating the GT-1000 with new Amp sims anytime soon.