It isn't pay2win simply because Horizons is a fundamental part of the game and everyone who plays Elite is supposed to own it. It's not just the most recent version of the game, it's also the way development is funded and everyone enjoying their free updates without paying for the expansions is a parasite (hyperbole!!! I consider everyone to be beautiful people). The term pay2win comes from games where you can buy specific buffs that will directly improve your chances against others, making twice as much damage, more healing potions, etc. You can buy these buffs immediately before or during combat. Horizons on the other hand is more like an expansion that raises the maximum character level, if that's pay2win than every MMO would be pay2win by your definition and you wouldn't have a point anymore.
If people want to compete they should get the newest version of the game. It's not a single perk or buff, but simply the journey and direction this game and development is heading. Don't like things changing? Don't buy a game that is in constant development.
Because we must always assume the worst. I am pretty sure that Zac is the reincarnation of Hitler, at least he didn't say he isn't. That's very suspicious.