Two points here:-
1. The S and X Performance models were always perceived to be cash cows, way over-priced relative to the standard models. Only those with very deep pockets could justify the upgrade cost. It was never a sensible option for most buyers.
2. S and X are now quite old cars in terms of their product cycle, especially the S. They are both due a major refresh soon and so heavy discounting at this stage seems like a reasonable strategy to keep them moving, particularly for the previously crazy priced Performance models, which now look like a great deal!
The Roadster on the other hand will be the latest and greatest toy for the wealthy and actually looks like a bargain at $200k. If anything I can imagine people flipping them for well over list in the early days. Just depends on supply and waiting list. I really can't see them discounting the Roadster any time soon after release. It would be a very bad sign if they had to resort to that with a brand new halo model. They will probably just build them to order as it's never going to be a high volume car at $200k.
The Model 3 is very different, because that is all about volume sales at much lower margins. As production continues to ramp up and number of cars on the road is now well over 200,000, prices are inevitably coming down. What would you expect? Okay it might have been handled badly with FSD etc, but it's not a big surprise to me that you can get an M3 considerably cheaper today than on initial release. But as another poster said, early adopters had a degree of exclusivity that newer owners are not going to enjoy as it becomes a common sight on the roads.