You are completely correct in that "one of our members" sent their M9 to Leica for a sensor clean & check and Leica sent a prepaid mailing label. I don't know if you're referring to me or not, but that was precisely my experience. I had called to ask about sending in my M9 to check the sensor, and after specifically asking if they could send a prepaid mailing label, they agreed and within 5 minutes, I received the mailing label attached to an email. To be clear, I mentioned that "a friend of mine" had been sent a mailing label and could they do the same for me.
My M9 was clearly not under warranty and, in fact, I had purchased it used.
It is definitely an example of inconsistency. My thoughts are that it ~may~ depend on who you talk to.