Or it could be that Lotus had to determine the actual problem, correct it in production. Make sure that it worked. Determine exactly how many cars needed fixing. Document that information. Manufacture the replacement parts. Get the parts shipping. File all the proper paper work with all the appropriate government agencies (on both sides of the Atlantic). Make sure all other legal requirements have been considered and taken care of. Then start the actual process of replacing the shifters.
Believe it or not, such things actually do take time. Even if they had wanted to swap them as soon as it was actually figured out that there really was a problem, things take time.
At least they are taking care of the problem.