What deco would likely be used and wanted for Galvatron if there is one?No, I'm pretty sure Flamewar was released in SG because there was no other way to budget that extensive a deco in any other line. She's a deluxe with a Battlemaster accessory, but only $7 USD cheaper than SG Slicer, who comes with a whole extra deluxe figure!
Whatever SG figures Hasbro releases, it's going to boil down to the decos someone there wants to see produced but can't work in to other lines.