I think the rule for the lapped cars during SC is quite clear.
If Mercedes pitted, Verstappen would have stayed on hards till the end. We dont know if Hamilton would have reached him. He would be a lot closer but he would have to try to overtake Verstappen, while having same points at the driver championship. Mercedes could have asked Bottas to crash during SC
As a last comment, I am impressed from the power of the new Ferrari engine. We have a lot of work to do during winter.