A variety of factors are considered when buying a new luxury EV, battery longevity being one of them. I do believe that the length of battery warranties are pushing the limit of what mfgs are willing to offer and it makes little economical sense for companies to offer longer warranties without a degree of guaranteed sales increase, especially in the states where most owners will never be able to avail of said warranties due to their cyclical purchasing habits.You think it's just battery longevity people consider? There are a lot of factors that affect BEV sales but a prime one is how long the battery will last. Right now the warranty is still at eight years for all BEVs, even for the bZ4X here in Canada.
Until that warranty goes beyond eight years, there has been no change to "longevity" or "peace of mind" to merit any increase in sales. These battery ratings from Tesla are not even backed by anything. If the batteries lasts a very long time, why then did Tesla removed unlimited mileage on the S and X in early 2020?
I don't know about future sales but I bought my friend's '12 CT200h for less than $5,000 USD in March 2020 when used car market wasn't doing well. I wasn't timing the purchase, my brother-in-law backed out and I was the middleman and I thought it was a good price.
Today, the cheapest listed in my province is around $10,000 and most are listed for $11-12K. And there's but 10-12 listed at one time.
Perceived and real reliability definitely affects the used car value. Someone with a '12 Cadillac CTS is happy to get $3-4,000 USD for this car. My Accord can sell for double that (probably in better condition) and the MSRP for the CTS-V was likely $7K if not more higher than my Honda.
That being said, your valid concerns might be something Lexus addresses on their CPO/used side as folks would be more reliant on longevity and actually use a warranty.