Would this be a religion ?

No. A religion is defined by law as having over 1000 patrons all using said religions name on their tax returns hence why 'jedi' is now an official and recognised religion. For gaming to become a religion you'd need to put A LOT of effort into this idea and somehow I think you'll struggle as by the time most people are filling out tax returns (census in the UK) they're not as HC gamers as they used to be.