I think the difference is you can't really interact with Phil. Even if a genuine fan spotted him in the wild, I think Phil would just say the bare minimum and nervously waddle away the first chance he got. If he ran into a troll in the wild, he'd aggressively complain about how stalkers won't leave him alone and he needs your support to stop these crazy detractors. If it was a fan, he'd passive aggressively complain about his privacy being invaded and how he needs your support.
Shifting gears back to the Xbox, there's a lot of reasons I don't think a fan sent it, but the biggest one is the timing. If it had happened out of the blue a few weeks ago, I'd believe it was a fan. But the fact it happened almost immediately after his begathon is a pretty huge smoking gun to ignore. He's also been signaling he planned to get an Xbox for awhile. Phil is an incredibly predictable person, which is exactly why so many people were able to guess he'd end up with a new Xbox from the moment the begathon was announced.