This appears to be for their business class and workgroup size printers, which makes a little more sense to have some manner of toner DRM in because they're typically leased or at the very leased serviced under some kind of contract. Sticking a toner cart some bean counter ordered from Wish or whatever in there is probably a nonzero probability of a malfunction (even if it's just the "colors being wrong") that'll result in a complaint from some PHB type who doesn't know shit about shit, and is thus something the manufacturer would really rather you not do.

Obviously I'd still rather they just not DRM anything at all, but this never applied to their consumer models as far as I can tell.