They might have dozens of reasons, but they already did what they did.

Some of the reasons could be:

- mitigation of US AI supremacy

- Commodify AI use to push forward innovation and sell platforms to run them, e.g. if iPhone wins local intelligence, it benefits China, because China is manufacturing those phones

- talent war inside China

- soften the sentiment against China in the US

- they're just awesome people

- and many more