Computer Science changes very little in 4-6 years. Computer programming might change - but if that was true then nobody would still be programming 3years after graduating because everything would have changed.

The reason for schools dropping CS is market forces. In the late 90s everyone wanted to do CS because that's where the jobs where, the market crashed and nobody wanted to do CS, then the market picked up and there were no CS grads, so wages went up, so people enrolled, then the market dipped .... Unfortunately there is a 3-4 lag in the system.

Of course if the schools taught CS rather than programming this wouldn't matter as much.

If you really want to get worried, check out how many schools still teach chemistry. Google/Facebook/etc can get by with self-taught programmers. The rest of industry can't get by with self-taught chemists.