I was thinking about this, as the US is trying to get a 3-way deal that involves Saudis-Israel having talks, a path to a Palestinian State and some stuff for the US. Maybe this person wouldn't be down with this plan.
Iran is a major enemy of all three of USA, Saudi, and Israel, so why would Iran's president have anything to say about that?
If this incident has any foreign involvement (which I doubt, considering weather conditions), then the first motive I'd assume is simple revenge/punishment rather than any specific strategic aim. It's hard to imagine whoever replaces this guy being in a position to be "softer" on Iran's enemies immediately after one of Iran's enemies was killed.

maybe putin isn't as bad as they say he is" s2g, we live in strange times