Via Previews World the coloured version of the Retiailer incentive cover on cover A is up - it's Aileron and Arcee:
It's pretty cool. Ever since I saw a tweet by Zama herself I can't help but ship Aileron and Arcee xDU
Sadly I don't have the link but the image was of Arcee holding Aileron close to her while looking at the night sky. Kinda like Chromedome did with the duplicate Rewind on MtMtE.