Let me simplify that for you...
... is apparently missing the point that this is a logical impossibility for any product that didn't stagnate 100 years ago.
Obviously that is not what I meant by a significant time.
When you buy an iPhone 8 next autumn, you are pretty much guaranteed to have the latest and greatest iPhone for 10-11 months from receipt depending on when you get it. At least 6. That is a significant time.
Now, let's call the Tesla 100D as, say, Tesla 7. If you order a Tesla 7 today, you are likely to receive it either just before Tesla 8 launches if you are near the factory (end of Q1), or if you live abroad possibly get your Tesla 7 only after Tesla 8 or even Tesla 9 has already been launched as the batching and shipping times can easily result the delivery spanning three quarters.
When people bought a Tesla after the AP1/P85D/85D they also had a significant time with the latest and greatest. But this past year big changes have been spread over every quarter: facelift Q2, P100D Q3, AP2 and FUSC (and small like glass roof, five-seater X etc.) in Q4, 100D and end of FUSC (plus small like end of ventilation) Q1, Q2 might be the HUD etc...
Even Tesla knows this and has at least in the past considered it. It prompted them to make a statement after P85D/85D/AP1 launch that this would be the only significant change in a year (it didn't quite turn out that way, but still it was significant time). It was a great buying opportunity for those who wanted the latest and greatest. Since then, especially in 2016, buying a Tesla has become much harder with big constant changes instead of just small ones.
My worry is, the quarterly big changes, combined with deliver times that are often longer than a quarter, means constant Osborbing of the product when something better is just around the corner all the time. Had some of these been grouped to make sure not every quarter is a major change, this fear could be alleviated. E.g. AP2/P100D/100D could have been grouped, maybe even Model S facelift.
A year later is not just around the corner. But a quarter later certainly can be.