When does the beta for andriod 10 come out for the galaxy s10 plus?
Samsung Memebers app usually will have a post and check this out:
Hey @Samsung_x8vhIEz, I hope you're doing well.
As Samsung's track record has shown, the Note line will follow the S serries shortly after. I'd recommend keeping an eye on these forums (specifically the Note 10 section) and checking the Samsung Members app for a registration banner soon.