Yes, it's betas late. Apple has launched for the entire developer community the beta 3 of iOS / iPadOS 13.3, tvOS 13.3, macOS Catalina 10.15.2 and watchOS 6.1.1; so if you have one of the previous betas installed you can update as if it were any stable version.
These betas leave about a week after the beta 2, and for now it seems that they will be minor updates than continue to improve the stability and performance of the systems (It seems that they focus even more on reducing the memory consumption of applications). Anyway, we always wait for some developer to dig through the source code and discover some surprise.
As always, we recommend not installing these beta versions unless you are completely sure of what you are doing. These are unstable versions, with a lower performance, designed to be tested and not to be used in your day to day. It is expected that the final and stable versions will appear within a few weeks.
Now available the third beta of iOS / iPadOS 13.3, tvOS 13.3, macOS Catalina 10.15.2 and watchOS 6.1.1