While it was not unexpected, on June 23rd the FIFA Bureau - the highest decision making body within FIFA - which includes the presidents of the six global confederations, officially approved new regulations expanding World Cup rosters to 26 players. They also made official the permanent change to five substitutions over three windows per game.
This move to a larger squad is in keeping with recent pandemic relief rules in place at last year’s UEFA Championship, which used 26 man squads, and the 28 man squads in place for the recent African Cup of Nations and the the South American Copa America held last year.