If Dr. Lisa Su, the CEO, wants AMD to submit to MLPerf they would have already submitted to MLPref. This tweet is about a discussion George had with her on AMD's open-source practices and code quality for the contributions they make.
AMD does have a history of spinning their wheels on the software side. Not graphics specifically (anymore), but definitely with their compute initiatives like HSA or even OpenCL.
I dunno what to think about ROCm. It does seem like they should have thrown the MI300 into the mix, but maybe its not ready.
The proof is in the pudding. AMD has excellent hardware and has had years now to get anything going. They didn't, and they don't so our best guess is, they won't.