That's a problem to be resolved by their legal counsel and often not even a fatal problem (e.g. work out some licensing agreement).
The first job of a startup is to understand how to solve a valuable problem. If the team is solving a valuable problem, they can figure out how they want to navigate even violation of licenses.
The first job of a startup is to understand how to solve a valuable problem. If the team is solving a valuable problem, they can figure out how they want to navigate even violation of licenses.
Everything else can be negotiated.