Seems, they want to adress the obvious issue of having Marrow in space (can't wear a space suit, if her powers keep poking holes in it), by having her make part of one with her powers.
Though i would prefer character development (or better redevelopment) for her over gaining the ability to turn into a Guyver to be honest.
Also once again during the current era, she sports yet another different look from her last one.