It doesn't necessarily mean that. It could also be that they attempt to block the rise of new platforms, and by doing so limiting the amount of platforms that they have to compromise.
That makes sense, and yeah I imagine the problem isn't the entertainment system.
I just don't get the the last paragraph. I don't know if using Linux affects their code being OS or not. If they're just running it on top of Linux and not modifying it, it probably won't be a GPL violation to keep it closed.
ELISA (Enabling Linux in Safety Applications) Project announced that Boeing has joined as a Premier member, marking its commitment to Linux and its effective use in safety critical applications. Hosted by the Linux Foundation, ELISA is an open source initiative that aims to create a shared set of tools and processes to help companies build and certify Linux-based safety-critical applications and systems
I imagine this means they're contributing both actively and financially to Linux.
Some thinkpads have official support for Ubuntu by the manufacturer (lenovo), which means battery optimizations out of the box, amongst other things. Might be relevant for your laptop.
Point it out explicitly in your resume. Don't expect them to figure out your github activity on their own.
It's definitely better to have open source experience than no experience.