Since Intel ME is proprietary stuff heavily protected and never licensed to someone else (and sold as a plus to enterprises that in this way can manage their assets), it will be extremely unlikely that a CPU made by someone else will include it

I'm not an expert on this, so take what I'm saying with a grain of salt. RISC-V processors definitely don't have Intel ME. However, as the RISC-V architecture is open source, some manufacturers could include their own similar coprocessor. Also, AMD doesn't have anything called ME. Do you mean the PSP (Platform Security Processor), which provides a similar function to the Management Engine?

It's still way too early days for RISC-V to have something like that yet. Somebody will probably make something like that eventually, but since there's no single corporation that controls RISC-V it will probably remain optional.