"it'll be interesting to see how this pans out against the current and new players in the A320/B737 market."
Most likely ( something like 90+% probability) that it will not "pan out" in any interesting way.
It is simply one more project used by "respectable people" as a source of kickbacks, that would be paid from gov-t contracts. The same thing happened with SSJ100 with virtually 0 interest from the industry. MC21 will be the same on the same level, I am afraid.