We have cats who have never been outdoors, save trips to the vet as needed. They don't get fleas or worms and they love soaking up the sunshine on the window sill. They watch hummingbirds and we have no problem with them trying to get outside.
I concur, keep the cats inside for their own safety. It will stop fussing in very little time and all will be well, and quiet.
Our current cat we took from our daughter when she married a man who is allergic. The cat was used to roaming free and had for about 8 years. He has a split ear and had teeth mising from fights he survived during his roaming years. But he settled down immediately and doesn’t make any move to go outside.