I wonder if the 'chip shortage' had anything to do with that... since they are running out just kill it now?
I was wondering the same thing? Been talking to a customer about an upgrade on an extruder. Has a pair of 551's and 9 BTM modules on it. Pretty sure I checked status on the 551's a few months ago and it was still active mature. Generally I've noticed longer notification dates.
Close to $10K for a 551 from local RA rep.