Supposedly Quinn will be back for S2
Here's an article from Dec. 2 that says Marton Csokas is part of the cast:
http://www.comingsoon.net/tv/news/791499-into-the-badlands-season-2-photos-reveal-nick-frost-and-more#/slide/1
AMC also lists him as part of the season two cast, although the post was made 10 months ago:
http://www.amc.com/shows/into-the-badlands/talk/2016/03/amc-is-going-back-into-the-badlands-in-2017
As most people know, we can't go by the episode count on IMDb because they can be wrong, or not updated, or the network/showrunner wants to make a character's survival a surprise and intentionally puts out misleading information.
Bigly.