According to Max Weibnach's information Samsung's flagship lineup for 2021 will include four Galaxy S21 devices – S21, S21+, S21 FE and S21 Ultra – and three Galaxy Z devices – Z Fold 3, Z Flip 3 and Z Fold FE. Three of those seven will have S Pen support, the Galaxy S21 Ultra is a sure bet.
3 of these devices will have SPen support.
— Max Weinbach (@MaxWinebach) November 15, 2020
Now, in and of itself that lineup doesn't exclude a Galaxy Note 21 from happening, but the inclusion of S Pen support on non-Note devices points in that direction. Another pointer is the lack of any information about any Galaxy Note development, per Ice Universe.
An unusual clue: There is currently no information on the development of the Note21 series. pic.twitter.com/RBzzwsg8Cg
— Ice universe (@UniverseIce) November 15, 2020
Of course there's a possible explanation to that theory as well – it's still way too early. But the Fold2 arrived after the Note20 this year, so we doubt that's the case.