Comment by bruce511

As it stands right now, if the code was under a GPL license, nothing stops them paying the author to get it under another license.[1]

Sure, they could offer a job as payment for said license, or just pay cash.

This approach would be "necessary" (for some definition of necessary) for GPL code, but isn't necessary for MIT code.

[1] this assumes there's 1 (or nearly 1) copyright owner. If there are multiple contributors, and no CUA in place, this approach is generally not possible.

Personally, and different people have strong feelings on this both ways, with GPL code I'd get contributors to sign a CUA. It keeps the door open for commercial opportunities like this, especially if the code is "mostly yours".