This is stretching my memory a bit but, as I recall, it had been open since the beginning and was still running in 2001. Then it became seasonal for a couple of years. I tended to go in February and it was never open when I went within the first few years of the 2000nd's. Then Alien encounter was closed to make room for Stitch and they reopened CoP permanently, at least to this point.
Attendance is a problem that is caused by a number of problems. The first is that it wouldn't be possible for Disney to care less about this attraction so they do not spend a nickel promoting it and, Second, and biggest, is that the public, when they are aware of it's existence, have absolutely no appreciation of history and what made Disney great.
If it doesn't cause your heart to beat faster or to bring you to near puke conditions, it is looked upon as not worth it, boring or lame. The saddest thing is that this trend will likely continue until all the old, what made Disney great, attractions are in the landfill. They can never be revived because frankly no one has the imagination active enough to create a story within a theme park ride anymore. I think it is a lost skill and I doubt it will ever return.
Anyway, all that to say that it is open, at least for now and still appreciated by a dwindling number of people. BTW, I may be off on the actual years that all this happened but it did occur somewhat in that order and somewhat near that time. As a post note...I rode it in 2006, the theater was 3/4's full and there was cheering and applause at the end. A good sign, I hope! Word of mouth made it popular and that could happen again, but, it needs to be soon.