Seems like MAI models from Microsoft are not going to be open-weight soon, but they are sharing a lot of details in the making of these models, which is a weird position.

They haven't even released the "big" version of Anteres, yet (and the "big" version is only 3B, so there's no way it's competitive with general purpose frontiers for vulnerability research). It seems like a research project. Maybe it's good for rapid triage and CI usage, but almost certainly not at all useful for general "find bugs" usage.