During the Nordic Game 2016 event over the past weekend Croteam have appeared to have confirmed that The Talos Principle will be getting a sequel. The announcement was made on stage by Croteam’s Alen Ladavac while giving a presentation on the original Talos Principle. The news was first tweeted by Damir Đurović, the managing director of Reboot Magazine, and retweeted by Croteam.
— Damir Đurović ®️Reboot Develop (@DamirDurovic) May 20, 2016
At this time it is unclear at what stage The Talos Principle 2 is in terms of development, so predicting a release year is basically impossible.