IIUC the SuperMicro BMC is different software on a separate third-party chip. So it's reasonably likely to be vulnerable, but not to this particular vulnerability.

Your IPMI should be on a private management network, at least. If you haven't done that, I hope you at least changed the default password.

Yeah, that's pretty easy on this generation. But there was a previous generation where the IPMI piggybacked on one of the main NICs, where it was a lot easier to accidentally expose that to unfriendly traffic.