I'm glad this question got bumped, since I can safely answer this with proofs.
I have a character named Faulk Slayer that was created on Guardia (which is now Bona) and I married him with a friend's character named Pam Archfox.
We both did this to get the outfit and using a character name that was an abbreviation of our real life girlfriends.
Eventually, I've stopped playing and so did my friend.
I came back to the game, but the character that he was married no longer exists, yet he still kept his engraved wedding ring and Newly Wed outfit:

My character still exists, so you can check on the website if you want to:

Pam Archfox does not exist anymore:

So if a married character gets deleted, the remaining one will keep his ring and outfit, but he won't appear married on the website.