No matter what we do, its always some people upset.
'Too many features for free' or 'Too few feature for free'.
As usual, we have ended up with way too much for free, as you'll see in the next few weeks..
It's the rationale between what you're making free and what you aren't. Things that obviously fit the theme of a DLC such as merchant changes in WoN or the tribes in CoP are reasonable DLC items. Things that don't and are independent features such as support independence (which almost universally gets applied to non-colony vassals in practice) or a UI change are not reasonable to package in a themed DLC.
Put another way: how does the automated papacy in any way contribute to the wealth of nations? It's a QoL change, not a significant change to how the game works. That's not the kind of thing you put in a paid DLC without getting people upset.
Most of us will buy the DLC, but quite a few are frustrated at what's being prioritized. Also rather than complaining that a given feature was free, people were complaining about what that "free" feature did to the game play via being implemented before it was fleshed out. Protectorates are an excellent example of that; we're STILL seeing bugs involving them, but in 1.4 where the outcry over them was the greatest they allowed distant insta warleader switches at any time, shattered alliances at the drop of a hat, allowed (and still allow in some cases) 100% annexation of giant nations, and cause permanent wars. The issue with them isn't that they're free, but that for many players that feature altered their experience in a negative way because it wasn't truly ready yet...and the patch history surrounding it is the best evidence.