The changes are thought to be as a result of changes mandated by General Data Protection Regulation (GDPR) laws, which apply to the storage of data by European Union companies, as well as companies whose customers reside in the EU. The laws come into effect tomorrow, by which point all companies need to be GDPR-compliant or face significant fines.
For an idea of the things you might be missing out on (if you’re an EU citizen under the age of 16 who uses Steam) here’s a list of upcoming PC games.
It looks like Valve will also require "parental permission" for users of the Steam platform located in the EU like Riot will with LoL, thereby making EU GDPR a super-COPPA. Users suspected to be under 16 may be locked out or otherwise have restricted functionality after Friday.
— wickedplayer494 News (@wp494news) May 24, 2018
Industry expert WickedPlayer494 stated yesterday that Steam users “suspected to be under 16 may be locked out or otherwise have restricted functionality after Friday.” I think it’s relatively fair to say, however, that the impact these changes will have on the wider community will be pretty light (not least because of the number of people who flagrantly lie about their age on online platforms).