Reshuffling that sentence for clarity:
The original MIDI protocol is widely-used by musical devices. MIDI 2.0 is a major overhaul to the original protocol.
There's also MPE which adds some more expressive capabilities to existing MIDI hosts, plugins, and hardware, which has some (small still) adoption. MPE is an extension to MIDI 1.0 to add polyphonic expressivity, and a lot of companies have added it in an ad-hoc fashion (what it offers is within the bounds of MIDI 1.0 "extended" modes).
So, unless you're living in the cutting edge, MIDI 2.0 will not be of much use for modern music production for the next few years at least.
E: that sounded like snark, definitely not the intention, Ableton supports MPE now and they were lagging behind. Roger Linn keeps a list of MPE/MIDI2 compatible software and hardware, every time I revisit it, the list has grow : https://www.rogerlinndesign.com/support/support-linnstrument...
Linn’s list appears to include MPE devices but I can’t find any mention of MIDI 2.0. I’m not sure why you’re calling this a list of “MPE/MIDI2 compatible” devices.
It sounds like you’re saying that MIDI 2.0 is widely supported; do you have a list of MIDI2 devices on the market?
MPE has better support, MIDI 2 not much atm.
There's also the Roland A-88mk2, with MIDI 2 support "coming soon" whatever that means.
The word “that” can refer to both original MIDI and the overhaul MIDI 2.0:
MIDI 2.0 is a major overhaul that is widely used by musicians.
…the original MIDI protocol that is widely used by musicians.