Nothing has been announced, but it's inevitable. Here are a few things going on:
1. Model 3 has been announced with more range in base model than the current base Model S. (210 miles for S60 and 215 for M3)
2. S60 now ships with a 75 kWh battery, which tells us they have enough margin to put it into the base model without killing their financial statements.
3. We've seen the website leak that supercharger credits are coming.
4. Locals are known for using superchargers for free charging even if it doesn't make sense based on the value of their time.
Again, you're right, nothing is announced or confirmed, but to me this change is only a matter of time. They will likely "lower" the price on all Model S' by unbundling lifetime supercharging in favor of a prepaid credit model and increase range on the Model S (at least the base model if not all) to be greater than the base Model 3.
I'm not saying that Model S range across all models should outpace the Model 3. I am, however, saying that the base Model S should be at least equal to the Model 3, and that we are likely to see that. A bump up from 60 kWh to 65 kWh upgradeable to 75 or 80 would enable this. They can easily lower the price of the S at the same time by unbundling supercharging. Imagine the headline: "Tesla lowers price and increases range on Model S, the world's fastest production car. Oh, and they are now shipping with AP 2.0 hardware."
Tesla has made it clear they plan another capital raise in Q4 - I wouldn't be surprised to see an AP v2 sneak peek, the range and pricing movements on the Model S, and probably an update on Model 3 reservations at the same time. They will need headlines to make the capital raise as easy as possible, and right after a successful/profitable Q3 will be perfect timing.