They can easily halt the software upgrades whenever they want.
Sure, but do you think that it would be a smart business decision to tell their clients: you know what, all those Nano S's you bought, are now useless? From tomorrow, you wont be able to connect to Ledger Live. Hahah, suckers.[/quote]
They can tell that for whatever reason the update is no longer compatible with the old hardware (see how Win11 update does it), they can simply tell in a year or two that old hardware is no longer supported, they can say nothing, just release update only for the newer HW (and make sure it won't work on Nano S), in the same way the older smartphones no longer get any kind of updates. There are plenty of ways to do it.
And Ledger's image is already going down, so they can't do much more harm to it
But there is still the issue of not being able to update your Bitcoin crypto app or install the newest firmware. In case your Ledger resets itself, you wont be able to configure it without accessing Ledger Live and downloading the BTC app as well. But yeah, Electrum should still work.
Clearly. From that point on, the Nano S user will be "walking on thin ice". He has to acknowledge that his device will - sooner or later - become thrash.
But what can he do? If he's transacting a lot, he clearly has to buy new device in the moment the old device is no longer supported. If he's using it seldom and any transaction can wait, all he has to do is to make sure the seed he wrote down is indeed good (easy to achieve with a Tails stick, offline), and wait for the device's final end-of-life.