I got this from a source:
Two filmmakers who sat down with a group of officials from Olympus “xxxx”. They said, the M5 mii would be a first and that they are waiting for the response from user, they also made it very clear that the M1 would remain their top model and that upcoming (firmware) updates will also make it very clear that the M1 is the first choice for video as well. 4K will be coming in the foreseeable future they are aware of the need for it, wether in a new model or via firmware, they did not state.
Makes a lot of sense to me.