Lots of things we don't know, and some we do.
We do know an actual Mark VI was designed, developed, and built by Randall/Mesa.
Leading up to the Pandemic it was known that Randall and team were working on a VI. Apparently,
it was completed, but the Pandemic and Global Parts Bottlenecks made new production virtually
impossible. So it was mothballed. Corporations cut production on a lot of goods, and then
production was forced to ramp up again when consumer goods saw an increase in demand while
lockdown was in place and governments were dumping a lot of $$ into the economy to keep it
afloat.
So, the VI couldn't be built when it was ready, and I am sure Randall (at that point and time) had to
have Gibson's ok for building and then distributing the new amp. Maybe Gibson told him to shelve it
for the time being. Maybe he had no choice. Maybe the cost of building it was prohibitive? We don't
know. It never saw the light of day.
Now, fast forward to when the Pandemic ends (mostly) 2 years later, and there is a VII.
Maybe some day we will know if Randall was forced (or convinced) by Gibson to redesign the VI into
the VII and parse it down for both build and cost purposes? Or if he had a few Pandemic epiphanies
and chose to thoughtfully redesign the amp from the ground up.