It's of course depending what people might consider "major", but I tend to agree.
I've said so elsewhere already, the market for the HX family members seems to be quite saturated (as in "everone who might ever been interested in a Line 6 modeling unit will by now have one"). I'm sure their POD Expresses are still doing rather well, but that's a sort of different thing.
What I'm saying is that, as far as the HX family is concerned, there's likely very little ROI, hence working on a bigger FW update simply won't pay off anymore. It's also not that you would still be able to redefine the game with 10y old hardware (the only exception being Kemper...), so all of a sudden everybody would start selling their other modelers and get a Helix instead.
In the end, Line 6 simply will have to come up with new modeling hardware (in case they want to stay in that business, which I would assume they do). And once that point is near, it's inevitable that the old hardware has run its course.