His point was that they had engineered the tires jointly with Pirelli. Sheriff also commented that the various electronic aids were programmed based upon the grip characteristics of the tire design.
The tyres have a Mclaren designation both in the nomenclature and physically.
Given the comments from Michelin it makes sense to me to be cautious, especially if you have to ask an insurance company for a 'contribution'.
Michelin will get approval, probably in 12 months or so.