I don't have a problem with it.
When animals switch ownes, names sometimes change. They will be confused for a couple weeks but they will soon understand that when you say this word, it means you are talking to or about them, and they'll respond. Animals are smart. They catch on.
I don't think its bad luck. I changed 3 of my horse's names and nothing bad ever happened. I kept 2 horses names because they actully fit them. If I rehome an animal or sell a horse, I let the new owner know that I won't be affended if they changed names. It's their animal now, not mine. Changing a name is the least of my concerns when I look at a seller/adopter.
I changed my cat's name from Rudy to Gandhi. He now responds to Gandhi. I changed my other cats name from Addison so Sage. She knows her name is Sage.