Boundaries can be a very good thing, but you have to choose them carefully. I'm not sure this is a good one.
Where do you think your wife should sleep (assuming she doesn't feel comfortable enough to share a bed with you)?
Have you read about sleep deprivation? Among other things, it makes people overreact to things and have mood swings. I would think it is in your best interest to promote her getting sleep.
I didn't hear how she worded her initial request. If she was rude, I can understand having a less-than-optimal knee-jerk response. But tone aside, what she is asking for seems reasonable if she doesn't have a comfortable bed available to her that isn't shared with you.
Me: 44 H: 44 Kids: 20, 16, 16, and 10 Together/Married: 22 years H announced he was emotionally detached and considering D: 4/4/16 H announced he is going to try to stay and reconnect: 5/1/16