For some reason the changeclass command (class selection via VGUI) doesn't execute class scripts on Battle Fortress. I've tested it on other servers, e.g. Drippy's which I think is still using the 2012 version of the HLDS, as well as on servers which have updated to this year's version of TFC. Result so far, it works everywhere except on Battle Fortress.

Mind I'm using the TFC client beta (Steampipe), which I guess will go live soon.