Just the last of the MPEG-2 patents have now expired few days ago.
From the MPEG LA:
Please note that the last US patent expired February 13, 2018, and patents remain active in Philippines and Malaysia after that date.
This does not mean that the usefulness of the MPEG-2 has ended for technology users. Hopefully now we’ll see greater MPEG-2 support in free software multimedia stacks.