I talked about this in the Reddit thread that popped up a couple of days ago:
I stated in the stream that this provides a look at what is being played most using D&D Beyond. We're not saying that this data is representative of D&D as a whole, but it is representative of what happens on DDB.
This does indeed include free accounts, accounts with only partial options unlocked, and accounts will all options unlocked - all accounts on DDB. We could share the data from those individual buckets, but for an overall look at what is being played using DDB across the 35m+ characters on the platform, this is accurate.
I can also confirm, that if we look at any of those three groups (free only, partial only, all), the ranking of subclasses is the same. Across all classes, the top subclass you see in the full image on this post holds true. So Path of the Berserker is still the top for Barbarians, College of Lore for Bards, etc. The only thing that changes by separating the groups is the overall percentage of the top subclasses.
Additionally, since this comes up a good bit, we do make a reasonable effort to cull "theoretical" characters by only pulling in "active" ones - which we define as those having made hit point adjustments, leveling up on different days, using features and spells, and taking rests. I know it's not perfect, but it is, as I said, reasonable.
Hopefully that will alleviate some of the speculation about how the data looks within those other parameters.
Thanks!