The "mia" persona on X has a specific vaguepost:

https://x.com/MiaAI_lab/status/2090736338328748220?s=20

> "I've got a confirmation on what model is Ox Alpha, but I can't share it yet. What I can say is this: You should ALL get really excited for this one!!! And it’s NOT what you think it is"

And others have said they have done analysis and found it to be GLM 5.x related.

That said, Mia said "it will be OSS" and "it'll run on 2x DGX Sparks" - well GLM 5.2 can run on 2x Sparks, but slowly and heavily degraded (quant). So doesn't really confirm/deny that suspicion.