S9 and note 9 made it to oneui 2.5 from 2.0.
Greetings of the day!
Thank you for sharing your concern with Samsung and providing us the opportunity to assist you.
This is with reference to your query regarding software update for your Samsung device.
Generally from your device settings it will notify you if there is a Software update available based on your Samsung device.
Samsung is rolls out updates time to time for the devices; however, it totally depends on the availability and compatibility of the device.
Kindly refer to the “Notices” section in “Samsung Members” application, you will be able to get further details about the eligibility and when the update will be available for your device model
Further assistance simply dial 011 SAMSUNG (7267864).
Samsung Sri Lanka Team