Possible addition to the Numbering and Updating debate?

For a couple of meetings, we've discussed various possible scenarios for 
how to updated WCAG for the 2.1 release (as proposed in 
https://www.w3.org/WAI/GL/wiki/WCAG_2.1_SC_Numbering)
I have something I would like to float to the group.

What if we made all existing 2.0 AA criteria into level A in 2.1 and 
introduced new criteria at AA and AAA levels?

Potential benefits:
Almost every jurisdiction currently measuring against WCAG 2.0 does so 
against Level AA. As far as I know, very few jurisdictions measure ONLY 
level A, and I am not aware of any that enforce level AAA.
So by making the existing A and AA requirements all become level A in 2.1 
we would be resetting the baseline without altering any numbering.

It would allow sites that currently meet 2.0 AA to immediately report 
compliance with 2.1 A, and then begin ramping up to meet the newly 
introduced requirements.

As was made pretty clear in our discussions, the numbers are crucial for 
cross-referencing and reporting on compliance. But realistically, folks 
focus on the level for targets and they use the textual name of the 
criteria for meaning. With the letter level now established as the yard 
stick for measurement, and level A established as backward compatible, we 
would be free to introduce numbering updates for the new SC in whatever 
manner makes the most sense (for clarity, consistency, etc). 

Making existing criteria all be level A makes things less messy. For 2.1, 
there are two dozen new Level A proposed and almost as many new level AA. 
If all those went ahead as proposed and you are trying to report both WCAG 
2.0 and 2.1 compliance for your product, imagine how convoluted your 
mappings are going to be, and how much additional churn that is going to 
create for teams. Such things will have a significant affect on adoption 
rates for 2.1.

I'm sure folks will perceive pros and cons to this, but I thought I'd don 
my body armour and throw it out there.

Michael Gower
IBM Accessibility