That's correct. Model S sales see sequential decline in last three quarters. There is no other explanation better than model S demand issue. Not only model S but the model X demand issue will pop up as backlog running thin in Q3. It's inevitable for Tesla to lower full year guidance by 5-10K in coming months.
Production around 2,000 week and improving. Model X delivery is now late September. S is September. We are at the beginning of July. Your demand arguments don't hold water, as usual.
If wait times were to become greatly reduced due to more rapid production, demand would likely be boosted significantly. A typical consumer doesn't start looking for a new car until problems develop with his old one. Then he'd like to be able to quickly trade in his old car and drive away with a new one.
There are undoubtedly many people who would like a Tesla, but are unwilling to wait while their old car further deteriorates. Not only would shortening the waiting time increase demand, so would having inventory on hand for prospective buyers who might be especially impatient.