At this point I feel like they might be afraid that Jones will beat Aspinall, to be honest. I agree that it doesn't make sense to protect Jon Jones at this point. He's got 1, maybe 2 fights left as a big draw. This is the time when you pit him against a young lion like Aspinall to build up the next generation.
It's always possible that Jones is ducking Aspinall, but that doesn't fit Jones personality. Jon is a narcissist, and there's no way Jon will allow himself to believe he would lose to Aspinall. I hate Jon as much as the next hater, but I just don't see Jones ducking Aspinall. I also don't see Jones going out of his way to fight Aspinall. Jon Jones wants money, so fighting big money fights makes sense for him.
If they truly allow Jones to fight Stipe and then Pereira, I can only see it being to protect Aspinall from losing to Jones, so he can be built up as the next big HW star.