My only guess is they have a parallel skunkworks working on the same thing, but in a way that they can keep it closed-source - that this was a hedge they think they no longer need, and they are missing the forest for the trees on the benefits of cross-pollination and open source ethos to their business.
Do you expect them to be able to capitalize on the AI fad so much (and quickly enough!) that it's worth dropping the ball on projects they're now doing well in? Or perhaps continue investing into the part of the market where they're doing much better than nVidia?
the hardware is already good enough, people would be happy to use it and accept that's it's not quite as optimized for DL as Nvidia.
people would even accept that the software is not as optimized as CUDA, I think, as long as it is correct and reasonably fast.
the problem is just that every time i've tried it, it's been a pain in the ass to install and there are always weird bugs and crashes. I don't think it's hubris to say that they could fix these sorts of problems if they had the will.