So Sailfish OS now runs on "feature phones" - or at least I think it will, maybe it will come with v3.0.
Anyway, since HMD currently have feature phones running 4 (?) different OSes, why not add a fifth?!
In fact, I personally would find this disappointing, since Sailfish OS is designed for smartphones and could easily power a Nokia Android phone (you can run it on an Xperia X, which is more powerful than most of the Nokia range).
Maybe, there is an opportunity for another "retro" phone from Nokia here. A phone with a horizontal slide-out full QWERTY keyboard running Sailfish OS... what would that remind you of? ;)