I doubt it is the case. RFM usually makes both style for all of their model. Maybe our Leo2A6M has a slight different layout that they want to take more time before release?
Just like how the RFM Tiger mid interior was released much later after their Tiger Early interior, even though the none interior versions were released quite fast back to back.
Curious why they wouldn’t do what say Miniart does where all the interior parts are on separate sprue. Then you can do every version as interior/no interior and offer the interior as a stand alone kit if you want
They already did with their Tiger and Panther kits. My Tiger Mid kit has all the spues to build the early and even the late version interior. And each of their kit has w/interior and w/o interior offer. If they didn’t release right the way, it is because there are differences to be modeled.