sanofi's manufacturing process defines the product. it's almost impossible to conceive that TEVA was able to duplicate the production process exactly. so while SNY must have standard manufacturing controls, production of a generic equivalent using a different manufacturing process should require added validation analysis at least that is my take on it
IF TEVA can/did reproduce L without violating MNTA patents then they have nothing to fear.
As others have suggested, SNY certainly can make L without using MNTA IP. They did it. But like Oreo's or Coke, exactly how they do it is another matter.