Is this item region locked?

Bump for no idea :)

The publisher is notorious for going overboard on region locks, such that eg a game bought in EU1 doesn't work in the US
So you're probably fucjec

The only relevant change from other versions of the season pass is the absence of the Rectifier.
There's no mention of locks in any SteamDB page, but, knowing Deep Silver, we can never be too sure...

I think it's only missing the "Loyalty - Girls Night Out" mission and "Rectifier" weapon.
Just like the German region locked one: http://www.schnittberichte.com/schnittbericht.php?ID=747167

Also, you forgot to create a mandatory thread-giveaway. Take this meanwhile: lZBo7