It's the same procedure as every year: Google releases new development builds for the latest version of Android, and the developer community begins digging through the code to see how it can achieve root. That's true for this year, as well, as Magisk developer John Wu has published the first canary builds of his systemless root solution for Android 11's developer preview.
After initial problems with bootloops, wrong binaries, and Pixel 2 phones, Magisk Canary now seems to be relatively stable and usable on all Pixel devices running Android 11. At the moment, the build also passes SafetyNet, but given that Google is working on improvements to the security feature that would make bypassing it nearly impossible, this might not last long.
This should bring all current Android 11 devices on board, no matter how you installed Magisk. Now upgrade to Android 11 with no fear!
Oh, there might be tons of other issues I have to fix, but at least it boots and it roots 🤪
— John Wu (@topjohnwu) April 20, 2020
You can download the canary version of Magisk on the project's Github if you're eager to root your Pixel running Android 11, but be wary — the solution is likely still buggy and can potentially lead to data loss.