I'm a bit late to the party. I just ordered an HX stomp (after watching untold hours of content about it, testing Native extensively, owning/trying other multi-fx units etc.), and I don't think I'd regret this, even if they came up with a new flagship a day after I received it. For a few reasons:
1) The amps and effects are already very good. Introduction of a new product won't make them less good (in the absolute terms). There're many comparisons of HX vs. real amps and/or other, newer multi-fx units (FM3, Quad Cortex) out there, suggesting, that even if there's going to be an improvement in quality, it can't really be so big that it would render Helix modeling obsolete.
2) "Good" or "better" is kind of a weird thing in the realm of music timbre anyway. Without going into a whole rant about this (I'm not the most qualified person, and God knows the world doesn't need another one of those) - there are tons of rackmount digital reverb/delay units from the 90's still getting studio use, either because they are still deemed "good" or "not good, but just the way I like it".
3) IR's kinda future-proofed all of the guitar effects units that are able to use them.
4) I'd need 3 more lifetimes to get as good as Tom Bukovac when it comes to guitar playing ability and getting tones as good as him... and he still has M9 from 2009 on his board. If the Line 6 "Legacy effects" are good enough for him they are good enough for me.
I'm sure that the new generation of hardware is coming. The fact that XL came our last year, coupled with the chip shortage, makes me think that the new units are years away, but I don't really know. What I do know is that Helix is already able to generate great guitar tones, and that won't change no matter what and when Line 6 will choose to release next.
