I recall being told that audio-technica ceased production of AT-637 because the original tooling broke. I also recall hearing a similar excuse from Shure when I inquired about V15 replacement styli.
The industry was well into CD sales by then, so the truth may be closer to the fact that sales of such relatively expensive record accessories were likely well along on the wrong side of the marketing bell curve.
Regardless, I'm thankful that they stuck in there with phono cartridge production (knock on plinth).
A-T did manage a few CD cleaning tools, including an 'electronic' one, the AT6050 'CD Auto Cleanica', looking for all the world like the bastard child of a Technics SL-5 and a Sony CD Walkman.
Cute little bugger, innit...