Whenever a Skill Style is marked as "Acquired through purchase, promotion, or event", they get a crown icon on the upper right whenever you look at them from the Collections Menu. Sometimes Skill Styles sourced from Tomes will list them as such, but other times not:

Does this imply that Skill Styles like Vigor, Dawn Orange (Season Zero) will never return again, and that Skill Styles like Veiled Strike, Autumn Gold (Season One) will, possibly from the Gold Coast Bazaar?
Also, here's an unrelated bug I noticed while compiling this:

Is this supposed to be Veiled Strike, Autumn Gold, or is it meant to be Death Stroke, Autumn Gold? Since the artwork was made for the latter, I assume that the name and description is a typo.
PC/NA — Lone Werewolf
Werewolf Should be Allowed to Sneak Prowling added in Update 50!
Please give us Werewolf
Skill Styles (for customizing our fur color) Added in Update 50!,
Grimoires/Scribing skills (to fill in the holes in our builds), and
Companions (to transform with).