First of all, welcome to the forum. Second of all, calm down! Yes, bengals can be extremely vocal. But it varies with the individual cat. Mine is a yowler and goes to town whenever he sees another cat in the yard. I'm sure he is loud enough for the neighbors to hear if they have their windows open. Mine also yowls when he decides it's time for his walk outside. That can be quite loud and annoying. That being said ... yours is not that way now and may never become that way. Many bengals howl for attention or food. If you keep them happy, you probably won't have an issue. People post videos that show the dark side of a bengal. Even I have one posted of mine crying waiting for his walk.
You can't spend your time worrying about something that might not happen or even thinking about rehoming if it does. Life is too short. You need to enjoy your little guy and go with the flow. The less anxious you are, the less he will probably attempt to wake up the neighbors.