Although it hasn't been announced for any of the Note devices, rest assured that the Note 8 will also get the Android 10 beta. Development has begun. The registration and rollout is expected to be a ways out though, likely end of December.
There is no ETA at this moment. It isn't expected anytime soon.
An official announcement will be posted here when registration is open for the official beta.
With all due respect, that screenshot clearly says for the S10 and this portion of the community is for the Note 9.