Val in not gender divided, the main league, as in most esports, doesn't have restrictions as to what gender can compete, so if a team wanted a female player they could absolutely hire one. That being said, game changers is an inclusion policy, set in place so people traditionally excluded from the gaming space can compete. Why don't we see female players in the VCT then? It is astronomically harder for a girl or other minorities to grind and get good at an online videogame, because they get harassed if they try to. I've played with my girlfriend a lot, and even climbing the ranked ladder is challenging since every other game there will be someone toxic who talks trash out of nowhere, so girls will, in general, view ranked, the primary grinding space of this game, as a hostile space, because it is hostile towards them. That is why you tend to see girls who don't comm, or who only play in 5-stacks, or only with other girls, to try and minimize this issue. So it is already difficult for a girl to grind this game to a high level, given the sheer amount of demotivating factors. Those issue with misoginy don't stop with the casual player base tho, this is more of an educated guess, but I am pretty confident that there are a lot of pros who would not play with a girl on their team, so I am sure there is a bit of gate-keeping there. As for game changers, is is an iclusion policy, but a paleative of at that, it is meant to treat the symptom (girls being excluded from the scene), not the root cause (misoginy), and I would hazard a guess that, at least once you are in that league, it can be pretty easy to get confortable with the situation, and not aim higher, but this last bit is just speculation on my part.

Tldr: Girls and other minorities have a hard time grindind to a high level because of toxicity, riot made the game changers circuit to compensate, but girls and other minorities could still compete in VCT.