I like dogs, but not yappy ones. And I definitely wouldn't like it if my husband decided the yappy dogs that I thought he'd given to his parents years ago were now a dealbreaker issue. If you never said the words "We're taking them back when we buy a house," then it's not fair to assume he knew that was your intent.
Yes, they're senior now, but three years ago, they were three years younger. Better communication at that point could have avoided this problem in a way that was better for the dogs. As it stands, if your parents can no longer care for them, they'll be moving from one home and family to another regardless.
If you're dead set on keeping them, and you also want to keep your husband, then at the very least you need to figure out how to teach them not to yap. Which you should have done anyway, a long time ago, before you dumped them on your parents. They probably could have done without the yapping, too.
You made this mess, OP, and you're probably not going to be able to ultimatum your way into getting everything you want. The only thing that might work is to ask your husband why he doesn't want the dogs, respectfully listen to what he says, and then find ways of addressing that specific problem. He wants them to stop yapping? You train them, before they move in. He's worried about not being able to travel? You pay for a pet-sitter. He doesn't like hair everywhere? You train them to stay off the furniture, and you clean the floor every day as needed. He doesn't want to have to walk them? You make whatever arrangements are needed to ensure you never have to ask him to do it. And you don't complain about him not helping enough, ever.