Maintainers simply may not have enough time to contribute. Most of them work full-time for projects. Updating this is probably a fantastic way to demonstrate your experience with OpenEmbedded 
(it always helps for the application, it did in my case!)
That’s wrong. The point of OpenEmbedded isn’t that one. Moreover this was attempted in the past and you’d find that getting a fully fledged DDS implementation running in a microcontroller is somewhat complicated and not really useful. That’s what the micro-ROS project is for which builds on top of previous experiences.