Choosing GPLv3 is a fully conscious decision. What other libraries may or may not do is not of much interest. Each author or organization willing to release open source code weights the pros and cons of different approaches and in this case the GPLv3 was chosen.

Having a license doesn't preclude being able to have a 2nd license for the platform. In most cases this pattern is filled with a direct negotiation between the parties (one interested in an acquisition with a different license, the other willing to re-license) Whether such a pattern fits your case is something which cannot be simply assumed.