It is reported that Ryzen 5 2400G and Ryzen 3 2200G have published.
It is wanted to install Ubuntu Linux on the new Ryzen system.
Can I?
its open source you should be as they would have lab tested it on Linux & other OS when they built them & sent them for testing before release.
just check the Linux forums I would suspect there be few people using & testing with diffremt versions of freeware like Linux Ubuntu etc. I would suspect nothing has changed