Where are you going to get an OTA to Oreo for the Note 2?
If an update is actually delivered over the air to your phone via the system update menu then it will be compatible. But those do not skip over updates: they will offer you each update in sequence until you reach the most recent. I'm also pretty sure that the Note 2 doesn't have an official update to Marshmallow, never mind Oreo, so despite you asking about OTA I don't think that's what you meant.
If, as I suspect, you are using a custom ROM, then it's just a matter of installing a different custom ROM. Take a Nandroid backup first in case the new ROM doesn't work or you just don't like it. Back up all of your data too as you will need to do a factory reset during the install.
If you meant "I've seen OTA update files for other Samsung Notes and wondered whether i could use one of those", the answer is "no, you can't".
So if you tell us a bit more about how you hope to update a Note 2 to Oreo someone might be able to offer more advice.
And Oreo for a Samsung won't be a/b anyway (and no custom ROM will change the number of system partitions).