IA’s forums were hacked and so that’s why they’re down. Their project continues. There have been quite a few remakes of KQ4 over the years but none of them have come to fruition. The newest of these is still in progress I believe, and you can probably find a thread about it on the AGDI forums if I remember correctly. I think that’s where I read about it.
I answered re: Space Quest 2 in the post you made in the Space Quest forum.