The pictures also provide a view of her alt mode that is identical to the trailer with the unicycle look in robot mode. Of note is no mention of any combiner mode which is making me think that the theory of the motorcycles combining is incorrect. It is starting to appear they are three distinct characters that make up for their smaller size with numbers and speed. At this point the only question is what is the name of the purple cycle (my guess is Elita-1).
Based on her bio below, the writers have chosen to keep her relationship with Ironhide that was suggested in the G1 cartoon "The Search for Alpha Trion." The bio info for Megatron is here and Skids is here. The picture didn't show the entire bio so I guess on what the missing words were as indicated by brackets.
Deluxe Chromia Bio:
Chromia is tough as nails, and always spoiling for a fight. She's [been] friends with Ironhide for centuries, and their reunion on Earth [is] one of the high points of the war for both of them. Now they [fight] side-by-side, hunting and destroying Decepticons. neither of [them] has ever been happier. The two robots make great partners, and [so] along with her sisters, are an invaluable part of the [team].