They bumped the major number. That's fair play. There has always been a lot of slouching wrt versions in python. That's not numpy's fault. Too bad they're getting the black eye for it. They could have avoided it by making a new dependency name ("numpy2"), but that sets a shameful precedent, so I give them credit for not copping out.
I viscerally understand how companies can get stuck and unable to change their products significantly because their installed base will revolt. It's a tough situation.
Well, if that's how you're going to behave, foregoing entirely obvious and solved engineering problems, you get to glue all the pieces back together when reality asserts itself. I don't imagine for one minute numpy folks didn't know what this would look like, and they did it anyway. Good on them. Breaking changes are necessary. That's unqualified. Necessary. If you can't afford a big blowup in your work then manage your work.
The Tree of Elegance needs to be refreshed with the blood of both users and programers. Or something like that.
We'd not get very far is the Linux Kernel made breaking ABI changes every year.