Reminiscent of how google maps (on cellphones) killed standalone GPS trackers, this may hurt Garmin InReach type devices quite a bit, not that there is a huge market for that in the first place.
I don’t think this will significantly impact inReach sales. The Globalstar network is not a serious competitor to Iridium for life-critical applications, and inReach-type devices have far wider operating ranges (try sending an SOS from your iPhone when the battery dies in any sort of sub-freezing weather) and much longer battery life.