Though if you actually read the stories, the issues are not the same as old problems:
P85D - VIN 62K, both replaced, but not due to milling, one was leaking and the other was causing a 12 V problem
P90DL - 2015 - Front drive unit got a software fault, Tesla replaced the drive unit on next SC visit even though the problem had not reoccurred
P85D - Rear DU coolant leak
S85D - Whining DU, thinks front, but hadn't taken it in
P85D - Sensor fault on rear unit caused the car to disable the front motor, rear DU replaced
Unknown dual motor - Failed temp sensor on the front motor caused it to shut down
Only 1 had noise, but hadn't had it fixed as of the posting. I didn't see any follow up. 4 were Performance models, 1 unknown. I also note at least 4 of the 6 were 85s, which most likely indicates they were earlier dual drive Model Ss. I believe most people took the 90 option when it became available, and that it was even more common on the Performance model.
No matter what car you look at, there will always be some cars that have problems. There are brand new Lexuses that have problems, though it's far rarer than with new Volkswagens. All we have to go on is anecdotal evidence, but if you look at what data people have been able to collect here, there were a lot more drive unit problems on cars built in 2012 and 2013, than since. 2014 saw a decrease in problems, and 2015 saw even fewer. It's still too early in 2016 to tell, but it's also notable that reports of problems are going down each year while the number of cars built has gone up. That clearly shows the rate of problems, which is the only factor that really counts, has gone down.
To really understand the problem you have to look at the aggregate patterns and not point out a few examples.
