I'm thinking now that just because Goldeneye is making it onto the service, doesn't automatically mean that Perfect Dark is a slam dunk to arrive as well.
There were 4 games that I know of on the N64 that Rare self-published. Perfect Dark, Diddy Kong Racing, Conker's Bad Fur Day, and Jet Force Gemini. I have a bad feeling we're only going to see Rare games on the Expansion Pack that Nintendo themselves published. So far we've got Banjo-Kazooie and Goldeneye, which both were published by Nintendo. You would assume Diddy Kong Racing would make it, but, Conker is one of the playable racers, and there's a 200% chance that Conker's Bad Fur Day isn't coming to the service
I would loooooooove if these games made it onto the service, but, I'm not keeping my hopes up. There's a much more realistic chance of getting Blast Corps, DK64, and Banjo Tooie though.
Not to mention, since Microsoft is currently working on a Perfect Dark reboot, the last thing they would want is a release of the original game on another system taking away talk from their reboot.