Pyro commented that it'd be easy to build, since it could use the same exteriors as the Yak-9T.
However, the recent news concerning Ki-84 shows that HTC has new standards now. Probably during the next 12~24 month period all of the AH planes will be updated to that standard - thus, no go for the Yak-9M. The Yaks will get new exteriors and interiors too!