Who’s calling it extended mileage and how do you know? If they are, wouldn’t it mean they’ll have the option available?
I'm not aware of an announcement formally stating that the Max will no longer be an option for the R1S and have never heard or seen Rivian officially refer to either "long range" or "extended range" with respect to a larger battery pack for the SUV. I'm not saying that either didn't happen. just that I'm unaware of it if they have.
With nothing official from Rivian, we can only read the tea leaves and speculate. There there is no longer any language on the R1S webpage that references the Max, and there doesn't even appear to be a reference to a battery pack other than the 135 kWH/316 mi Long Range any longer. That seems to indicate at least a delay in the Max, if not it outright cancellation buy again, with nothing official from Rivian, that's speculation.
In several chats with CS iover the past few months, more than one has hinted that the the R1S will not be offered with the Max, and that Rivian is working on a replacement with less capacity, dubbed the "longer range" pack internally. That too is far from being authoritative, though it is consistent with what we see (or more accurately, don't see) on the R1S web page.
Informed speculation is the best we can do absent official information from Rivian, and until we hear from the company what's on the cards relative to a longer range R1S, I'm keeping my reservation for the R1T Max in place. There is more speculation (surprise!) that Rivian plans to send delivery window updates in the next few months, so perhaps we'll know more soon.
