I would guess the important thing here is "it is subject to the same penalties as the things we previously said enable discriminatory practices, and so we get t

I would guess the important thing here is "it is subject to the same penalties as the things we previously said enable discriminatory practices, and so we get to reuse that abstraction," not so much "we believe, as an abstract political argument, that this is in fact discrimination." It's like how a pidfd is a file descriptor. Is Linux saying a process is a file? No, but it's saying that the usual things that apply to file descriptors - how you pass them around, how you name them, etc. - also apply to pidfds, and anything that works with file descriptors in the future should probably also work with pidfds. It's not saying that OS professors should teach "Really, a process is a kind of file." In the same way, philosophy professors should not, on the basis of this law alone, say "Really, refusing to post salary ranges is discrimination." (And a "discriminatory practice" is a specific abstraction separate from but usually connected with "discrimination" in much the same way that a "file descriptor" is a specific abstraction separate from but usually connected with "files".)