What will be the consequence of not returning or ghosting my employers while on leave?
Your reputation will be shot, and a bad reputation will follow you for years
Most industries are very tight knit, and people tend to transfer between companies within the same industries, plus there are trade shows where people talk, et cetera. That is enough of an unprofessional move for it to become gossip.
"we had this one employee named Aurora who ghosted us! Can you believe that? Didn't say a word, just one day went off on vacation and never came back!"
"Aurora? Well, that's odd, we have a new hire by that name...."
This happens more often than you may think. I have bumped into people in different companies for years who I have known from elsewhere.
Your most valuable asset in business is your reputation, treat it with care
When I am hiring, every last person scheduled for the interview can do the job, so my job as an interviewer is to pick the best fit personality wise. If you have any sort of character mark on your reputation, I'm not even going to consider you, even if you are the most skilled candidate. How do I know you're not going to ghost on me as well? Sorry, I'll pass you by for that B- student with mediocre skills and a great work ethic with a personality that lights up the room over you any day....
This is why you don't ghost anyone.
You always act professional regardless of how you are treated because you want your hands clean. The whisper network is a very real thing, and your reputation will precede you, for good or for ill. Make sure it's for good