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.
At which point why tie yourself to the competitor's language. Probably much more effective to just write a well optimized library that serves the MLIR/whatever is popular API in order to run big ML jobs.