Well...those aren't 416 barrels. Those are 16" and not 14.5".
I'm 99% certain that HK has never made a 16" 416 variant with the M203/M4 profile step cut...at least not outside the early prototype (certainly not during production least of all 2017). And given that that's an extended 11" rail, the profiled portion in front of the step cut but behind the muzzle is far too long for a factory 14.5"
A factory 14.5 416 barrel:
Brownells 16" Isotoner BS:
And I'm pretty sure that if they were 2017 mfg, they would have polymer ejection port covers and not metal/milspec. Though you can see the "AG" date code on one. Maybe he doesn't understand date codes.
Whole lotta BS