That would be a new record for a 75 for sure.
To be completely clear, when you say "get 200 miles out of it" you mean that a 100% charge indicates 200 range miles on the display?
What are your regular charging habits?
I charge at home from a NEMA14-50 plug and set it to 30A. I normally charge to ~75%. I've never been a heavy supercharger user; probably less than 35 times across the life on the car (just over four years).
Recently went on a short road trip: almost exactly 100 miles door to door and almost exclusively highway driving. Charged to 100% and entered the destination in the navigation. Made the drive under normal conditions (temperatures in the 60's, speed 70-75mph) and arrived with 51% charge remaining - exactly as predicted by the navigation computer before we left.
When it was time for the return trip, the nav system warned that I needed to stay below 60 mph to reach my destination. Luckily there is a supercharger at the midway point and just a short detour from the straight route so I stopped there instead of driving so slowly.
This is a repeatable exercise for me; I've done this trip three times in the last six months and the battery performance is the same every time. When I shared this data with Tesla they claimed to see zero problems with the battery pack.
To aerodyne: the car went out of warranty last month but this is an issue I raised more than once with Tesla while it was still under warranty.