To me, landing on the C&C website and finding nothing but The Ultimate Collection and the MMO was like the day, a decade or so ago, when I typed westwood.com and ended up on the EA site. My heart sank thinking that it was the end of an era, and unfortunately in that instance I was correct, though not immediately, but in a steady decline.
I never joined the forum, simply dropping in from time to time to find info for the classics and to see what was new, however the loss is quite significant to the community regardless of good, bad or ugly content. Ultimately it was a record of all that had come to be during its existence, and a database of useful insights/ opinions/ methodologies etc.
As for the future, I personally do not hold the same optimism expressed by Plokite_Wolf in another thread with regard to upcoming developments. Instead I think that this is just "clean-up" by EA to ensure that newcomers to the franchise are not put off by seeing links to null content, and messages from unhappy people in the forum.
However, as the good professor once said: "Time will tell. Sooner or later, time will tell......"