There's that. It's good that the gun is a separate piece, since in a lot of cases I feel that the design of a weapon is compromised for the sake of storage, although the buster gun was a good execution of this idea.
Looking at pictures that have been released since, it's clear that this is an all-new mould and not just a heavy retool. I'm particularly curious to see differences in the upper torso, since there is no longer a need to accommodate a light and sound board, two AA batteries, and the Mech-Alive gimmick behind the windscreens.
That would be nice. I'd be up for that.
I think the issue with the AoE leader mould is that Optimus was a new design that the toy designers didn't have enough time to work with to properly translate into a toy in time for its intended release. This is an issue with movieverse toys, and it's why figures in subsequent movies with the same CGI models are better. Examples are RotF leader Optimus and voyager Starscream, HftD leader Starscream and Battle Blades Bumblebee, and now TLK voyager Optimus.
The first two MPMs were the Japanese releases of HftD leader Starscream and Battle Ops Bumblebee, so as far as the Japanese consumers were concerned, they were new moulds and not cheaper toys with nice paint jobs. Both had pretty good engineering.
This figure and MPM-3 are all-new moulds.
Someone on Reddit posted this album. I'm not sure where some of the photos were taken. Note that the figure in the display box is mistransformed.