why would I pay for my business.
Uh, because you wrote it while in the employ of someone who provided you with an office, support staff, possibly a salary and benefits. In other words, they gave you the ability to do something you probably could not have done on your own.
Obviously you will find out what will happen when they leave. I have just related my personal experience as well as what I have observed from agents I know.
They may give you a pat on the back and wish you well.
Or they could kick you out the door and dare you to even try to take any of those accounts.
Either way, I am sure you will report back.