You don't have to sit tight until December to start your 2020 retrospective. As promised, Apple Music has made its automatic Replay 2020 playlist available to subscribers through its beta web player. You'll have to visit the site through a mobile browser to add the playlist (the desktop page seems stuck on Replay 2019 as we write this), but you can get an automatically updating look back at your top tracks of the year well before spring has even started.
This is partly Apple's attempt to get ahead of Spotify's own year-in-review playlist, and it probably won't be too useful at first when it will only reflect your mood from the past few weeks. Nonetheless, it could be helpful to show how your tastes evolve over the year -- not to mention a readily accessible favorites playlist that reflects what you've been enjoying recently.