The question about refreshing/reworking the current Model S/X actually makes a lot of sense. I will try to explain from a few different aspects:
On Energy
1. V3 and upcoming SuperCharging tech are not supported on Model S/X because of its battery pack.
2. Tesla just bought Maxwell, a battery company famous for its dry cells, might very well make their product useful.
3. Model 3 has greatly improved its energy efficiency compare to Model S/X(can elaborate if needed) with its new battery pack and platform(talk about next)
So even just for energy improvement, Tesla has every reason to refresh/rework its high-end product lines. For one, It will be kinda weird to have Model S/X denied from new improvement on core tech improvement. And also because Model S/X are not mass-produced compare to Model 3 and Model Y so they are good test fields.
On Platform
1. Model 3 is built on a 3rd gen platform with far shorter wiring, and fewer components and far better efficiency compare to Model S/X, which makes a rework for Model S/X on a new platform very much reasonable. Can't have the high-end worse than the mass-production, right?
2. the 3rd gen limits to only Model 3 and Model Y, both mid-size vehicles that can't replace the places of Model S and Model X. So the demand will likely to stay around. And if Tesla doesn't rework Model S/X, or simply, give up on updating them from a fundamental level, the market share of that demand will likely drop. It's a risk Tesla unwilling to take for that their current publicity is built upon building the best EV. Model S/X are Tesla's face.
So it's very likely to happen but likely in a distant future, for that Model Y and Model 3 being mass-produced at a declining cost are paramount for Tesla's stock price, and obviously, survival.
