I'm too lazy to go digging to find the source, but some of the earlier articles, plus the now mostly deleted audition videos suggested she actually takes the batsuit off Kate's corpse. I couldn't say for certain that's what they had planned, but it sure seemed that way. Not sure how that was supposed to translate to "likable". Regardless, the implication was Kate was KIA, so if 'Ryan' didn't take it off Kate's body in the original story plan, guess she stole it from whomever did. Disrespectful to kill Kate like that regardless.
Anyway they backpedalled on killing Kate now, because it was a bad look to "bury your gays". So they a burying her without saying they are, they are just erasing her and pretending no one in her family cares because 'Ryan' is so much cooler and they all love her more, or something along those lines, would be my guess. They'll probably also throw in a line about how "proud" Kate would be of 'Ryan' no doubt, to try and force the audience to love her too.
Since they apparently have no plans as to how to resolve Bruce's disappearance, I suppose Kate is likely there with him, in a void of unresolved plot threads. What a place to be.