Your app licenses are associated with the account that you use to generate the VPP token. If you change accounts the license entitlements will also change to whatever the other account has.

TL;DR: Changing accounts will cause a lot of issues, and call Apple before doing things like this.

You can call Apple and they can change the account over for you.  It take some time to accomplish however.

Yeah definitely want to reiterate what's already been said in calling Apple about this! It's better to play it safe and try to avoid any potential disruptions for your users as much as possible!