Humble usually indicates whether a game is regionally-locked either by placing a "Not available in your region" mark on the box's cover and/or mentioning a potential region lock in a bundle's requirements page.
Okay, I'm a bit pissed off because I got no such indication when purchasing the bundle, but something very weird seems to be going on.
I've always used paypal (with a US address) on steam and on humble, and I've never had any issues with purchasing and redeeming games on steam. Since it is hard to top up my paypal account regularly from here, however, this time, since I've finally gotten a credit card, I decided to use that. Unfortunately, problems.
After buying this bundle and redeeming the few games that I don't already own on gog one by one, after getting the KQ collection (only own 7-8 here), which worked, Police Quest games, Phantasmagoria games, all worked, Gabriel Knight 2 (already have 1 here), which worked, I got to GK3, which wouldn't redeem. After clicking to activate it, I got a weird dialog box which said "The following games could not be activated in your region" or something, except the place where the games should have been listed was blank. Continuing with the games I don't own, Caesar 3 & IV didn't work either, with the same issue.
After investigating this, I find that GK3 and Caesar 3 & IV are region restricted in Pakistan. But so is GK2, which got redeemed. And so are a number of games I've redeemed on Steam that I've found out now are region restricted and not available for purchase from Pakistan. I figure it is because I've always used paypal when purchasing steam games, and even in the store, I purchase by adding ?cc=US at the end of the links.
Now a bit of an odd request after such a long post, but if someone has GK3 not redeemed yet, would they be willing to see if a swap would work?