Hank Scorpio

Well, based on past events you may or may not be ok. I can give you a few examples I have personally experienced with premium characters that may or may not help. For Dr. Nick, I did not purchase him until he was packaged in a Gil deal with Krustylu Studios and Sideshow Mel, and a cannon. Anyway, I bought Dr. Nick and I did get a questline for him that was released much earlier, during the Squidport expansion. For Hank Scorpio, I purchased him during the Black Friday sale last year. And I was rewarded with an additional storyline during the Christmas Event in 2014, and they storyline was originally released during the 2013 Christmas event. For the Stonecutter skins, I earned all of the skins during the event, but did not own either Arnie Pye or Jasper. I know that if I had purchased them after the event, I would not have received their Stonecutter storylines. However, when they re-released the Stonecutter skins and items earlier this year, I was able to complete each of these characters storylines, after the event ended, but during a released second sale.

So from the examples I personally experienced, the Squidport expansion was a permanent addition to the game. While the other storylines were event based. Thus, I would think that maybe the questline with Hank Scorpio will only trigger during this event, or if they have another Superhero event or sale again. But that is just my personal opinion, based on my past experiences. I could be completely wrong.