I disagree. I think projects can be over planned.
It’s probably semantics though Bill. I think your reference to iterative planning is sound, but I don’t see where “I don’t think you can overplan a project” follows.
Primarily, overplanning occurs when trying to do a fairly detailed design or work packages for work months or even years out into the future. The more time that exists between now and when it’s to be done, the more likely it should be a high-level planning package. Spending time on detailed design before you know enough is pure muda (waste).