Though the Samsung note 9 is capabe to run android 11 it don't have the update. But the samsungs new mid rangers which have lesser performance than the note 9 will get the update. I like to request from the Samsung to give android 11 update for the note 9 also.
Bro Note 9 released in 2018 with Android 8. So according to the Samsung's software support policy it will get only 2 OS upgrades. You are in Android 10 now, so you won't get any OS upgrades again. You will get security updates though.
The new "3 OS upgrades per device" policy applies to ALL devices released in 2019 and onwards. So the newer devices are obviously entitled to their 3 OS upgrades.
