Despite being largely absent from the forum for some time I still kept an ear out for Jim's stuff and I even rewatched older content of his, or rather re-listened to it, in my day to day once in a while. And I know this sounds a bit of a stretch, but I've always had a good attention to detail. And it really intrigues me that this man sounds a lot like Jim even without messing with the audio. Like you said, the inflection, the accent. His manner of speaking. If this ISN'T Jim, it's someone with a very spitting image way of talking and personality. And it looks like he's been around for some time while the Metokur channel rots. Can't blame him. Jim never liked staying in one place for too long, one account for too long. Hell while searching for archive stuff of his I found names I actually either didn't know(SteveJobsGhost)or forgot about(BrightSideBob).
He ditches and returns often enough that I can imagine he just ditched Mister Metokur and rebranded.