Update on this one. it seems 2020.4 will block the install according to the documentation on this page.
That means 2020.3 or older will be the only versions you can install on an M1 mac alongside the web edit features which can be access via the browser.
In this video, I test whether you can install and run Tableau on a new 2020 M1 Macbook Air with 16GB of ram and the base storage.
I recommend not relying on this as evidence that you can use in production workflows and until tableau confirms it works and supports it stay well away. That said if you plan to use tableau prep or tableau in general entirely in the browser then it really doesn't matter what processor you're running.#m1mac