Are people thinking it's the same mattress that Robert slept on? If it's the same bed frame/headboard, I don't think it's that odd, especially not in this family.
I also didn't find it that odd that Kim asked Bruce about gender reassignment surgery. This is, after all, the same family where Kourtney and Scott made a sex tape impersonating Kris and Bruce - complete with strap-on; sisters played with their little brother's penis, a tween-aged Kylie danced on stripper pole while her older brother taped it; and in another fun, family bonding moment, Kourtney, Khloe and the evening of the waxed labia.
Kris Jenner made me teary-eyed and I don't even care for her. I can fully believe that she didn't realize the extent of Bruce's feelings, especially if he didn't share much with her. As others have stated, some men enjoy cross-dressing but never desire to be a woman. Kris may have tolerated Bruce's proclivities as harmless, especially since she said they couldn't keep their hands off each other when they met and they had two children and a consistent sex life. If she had moments of doubt, she had real life experiences to calm her doubt.
After his conversation with Kris, Bruce practically glided out of the room. He was visibility lighter. I don't think this decision is as easy as setting it aside for the sake of fame and fortune. I imagine that much like anyone who denies a major part of themselves, you get so used to suppressing it you don't realize you're doing it.