I agree with Theo and like to point to the "Tracking" and "Paint" sub menus which only have one tool each.
Maybe that cleanup could be extended to other context menus as well? I remember that Firefox once recorded which menu items were clicked the most to help them arrange the menu items better. Such anonymous usage statistics could be collected by Fusion during the beta if a user is ok with that.
I can imagine that
some items in menus like this could be moved to sub menus. Or that users have grown accustomed to either click "Animate" or "BezierSpline" in an input's context menu but never need to have both items (since they are seemingly doing the same thing) while "BSpline" is in a sub menu, lumped together with modifiers that just by their names sound like they actually modify values.
I think it was Stuart who once explained the reasoning behind it but from a UX point of view...it's still weird. To me at least... and I'm probably totally wrong in assuming everybody uses the context menu the way I am or is sometimes confused by them in the same way. But here's more to get this off my chest

- when an input is already animated, the context menu has the "Insert" sub menu which isn't visible on non-animated inputs. Using the same logic, wouldn't it make sense to hide the "Modify With" and "Connect To" sub menus - since neither can be clicked and they just make the context menu larger?
- the publish item is inactive, but there's now an Insert -> Publish item. Couldn't the top-level "Publish" item be used to insert a publish modifier on animated inputs?