There is a "Join the MMA" link at the bottom of this page.

Thanls for your answer. It is fantastic to know that!
How could I join the MMA to contribute to the discussion?.

Best regards.

The MIDI Manufacturers Association is embarking on a developing new version of, extension to, or replacement for the Standard MIDI File. The primary trigger is adding support for MIDI 2.0. But we recognize that there are other areas we could improve functionality in a new file format. There are many ideas for consideration beyond just the MIDI Data. Additional considerations could include lyrics, score markings, chords, other media, security features, and more. Developers with interests in specific features should join the MMA to contribute to the discussion.