Roleplaying games for instance have entire lists of them, and I am sure there is a video game somewhere that generate them procedurally, making the list effectively endless unless you have some kind of notability criteria. There are hundreds listed in here https://tvtropes.org/pmwiki/pmwiki.php/Main/MegaCorp and it is just the megacorps, there are many more that are not "mega".
But generally, I agree, I was just commenting about how many there are and how easy it is to create new ones, a lot of us probably made a few of them. Making a fictional brand is a common exercise in business or design schools, it can be done in creative writing, as an example for a presentation, in a role-playing campaign, or just for fun. If anything goes, we may be in the billions.
It is canon to my game, but I don't expect the Fictional Brands Archive to be canon to my game. Just the same as I'm not going to edit the Skyrim wiki and put down that the Dragonborn is wanted by all the guards in Winterhold and posseses a world's best collection of cheese wheels, just because it happened in my game.
If the playthrough becomes notable enough then it's not a problem since there won't be billions of those.