You're probably correct! I've participated in 2 of these types of forums so far in recent decades and once the model is totally dropped - so does the participation in these forums.
It was neat being a part of the first Lincoln LS forums and it was neat to share ideas and such on those forums, but they quickly died down after the LS was discontinued. I still have my 2000 LS.
My winter beater - a 2009 MKS has been a great car too. This forum helped get me through a few issues. It is a shame it too seems to have 'discontinued' with the MKS.