Yes, that's the next best thing we have: I was hoping for something more along the lines of the sets collection tab, where each set is displayed in its own section so that you can see the completition progress.
With the outfit styles tab it's a bit messy to understand what you need to complete a set.
Plus it does not seem to list the crown store styles, like the Potentate Smiling Viper Helm or the Sentinels of Rkugamz.
Oh well, I guess it'll have to suffice. Thanks for the help!

There are four classes of outfit styles...

1. Those acquired through motif knowledge: Can be tracked using a motif knowledge tracker. CraftStore, for example, or Character Knowledge (not yet released).
2. Time-limited in-game earnable ones: e.g., Ebonsteel Knight body styles from the recent Midyear Mayhem event. Their appearance in the collections UI is inconsistent: some of them will appear, but some will remain hidden until earned. These can be tracked (along with other time-limited collectibles) using Event Collectibles.
3. Regular in-game earnable ones: e.g., battleground styles or certain quest rewards. You can generally see them in the collections UI, though buried amidst the motif ones. I don't think any add tracks these, though I know of someone who made an (unreleased) modified version of Event Collectibles to track the Battleground ones.
4. Crown Store exclusives: e.g., weapons packs. There's no tracking of these, and I don't think it would be a good idea to track them.