I'm curious if there might be any potential backwards-compatibility with this figure and the upgrade parts that came with the Takara figure. Normally I wouldn't think so, but they made Commander class Armada Optimus backwards-compatible with the original Armada Overload, so who knows?
The gauntlets might be possible to fit onto the arms since they were just attached by 5mm pegs slotted into the fist holes. The winged backpack, however, is a bigger mystery.
The Gauntlets are a maybe but the wings, I doult it, because that connected on by OP's light bar and from what I can see, looking at the pictures, there doesn't appear to be a means to connect the wings to him, but then Hasbro & Takara might be planning to release a remold further down the line where OP comes with modern verisons of the upgrade and likely a alterative head where he has the face plate and likely a more shiny paint deco!
I do kind of hope with these animated style in legacy, they try and do Shockwave from animated, the original is still awesome to this day and it would present the desginers a challange as they got to do, two robot modes and two vehicle modes, all as one figure, animated Shockwave is one of my favourte figures from that line, he such a AWESOME figure and as Shockwave, he towers above pretty much every modern voyager class and leader figure, thou he shorter than commander class Jetfire, but then Jetfire is a big fella to start with, thou I would also like for Legacy to try their hand at a modern RID2001 Megatron/Galvatron, having all ten modes, as it stands, that is the figure with the most modes in a single figure and its a unbroken record for over twenty years now!!