I had the same answear from MBUSA when I called them last year before I had service B done at FJ dealer in Newport Beach, CA. This time I did not bother to call MBUSA for clarification. I print Gilly writting in this topic to bring with me to show to service advisor. But I did not need to show the new guy any of Gilly opinions, he told me MB pays for these brake and coolant flushes at 2-3 years interval as recommented if the car is in for either service A or B when I asked him who will pay for it.
The best way for you is to print Gilly writing in this topic to show to your service advisor at your dealer along with Maintenance and Warranty Booklets in your owner packet. You should read these 2 books, then you will have a good understanding about MB Maintenance Commitment plan.
If you like to have a copy of my receipt that shows no charge for brake flush and coolant change, give me your fax number by PM, I will fax it to you to show it to your dealer. I am supporting you in demanding that MB should stand behind their commitment.