I don't know. Many contents here are more than borderline/hackish but since useful and not harmful, they are tolerated.
CZ is essentially a reskin of CS 1.6 with singleplayer missions (which bots are used for).
For built-in CS Bots and even others features, I think it's fine now because of several reasons:
- GoldSrc is very old and not really supported by Valve anymore, so they don't much care
- Most of the people have already CZ because of Anthology/Complete pack
- You can't actually buy CS 1.6 alone anymore since forever (webarchive
can trace back up to 2008, and likely before that, probably since 2004 when CZ was released). They are sold together. So among the daily 30k players playing CS 1.6 vs billion of sold copies, there is a little chance they don't have CZ really.