Although I am a subscriber to Ancestry for the census returns, I haven't received any e mails about this so I don't think it is particular to subscribers.
The Ancestry BMD's used to occasionally be linked from FreeBMD when their server was busy and they used to direct you to Ancestry. I am sure that the information was the SAME information as FreeBMD, and therefore is incomplete. It used to be presented on Ancestry as lists, and not with the images though.
This link didn't appear all the time, and it's not there tonight as I just checked. I have just been into Ancestry and I only did one free search before it chucked me off whereas I got information from FreeBMD straight away. It's annoying that there is so much traffic that somebody couldn't even get a census return.
The records are only up to 1983 whereas the 1837 site is up to 2002. The 1837 site is part of a larger site which was originally set up some years ago for solicitors who needed to search for probate information, so it was not started with genealogy in mind.
I don't think Ancestry is doing this out of sheer goodwill - I would think there is something in it for them somewhere.
Honeybun