Yes, its that easy. They never responded back to me and changed my last name.
I was surprised, since even to change my name on all the hotel reward programs I had to provide marriage license.
If I had to guess, perhaps they only contact you if it seems suspicious....such as changing first name and birthdate....which could mean you are transfering account to family member.
As a side note, I wish I would of kept my maiden name for DM since my passport was my maiden name. I had to get an entire new passport as if it was my first.