They’re still very much alive and well, although I-R no longer owns them (Allegion’s the current holding corp, alongside Schlage, LCN, Steelcraft, Ives, and a few other names in the door/hardware space).
As to why? This was used with their delayed-egress (Chexit) and alarmed-egress panic hardware as the alarm horn. (The current part for that is still called the 1910 series, which is still a rebrand of something, but I’m simply not quite sure what nowadays.)