This is really stupid. There's an actual reason why they have a Women's Championship but they don't call the other one the Men's Championship. It's the same reason there's an NBA and. WNBA. The NBA is NOT male exclusive. There's no rule that says only men are allowed to play in the NBA. Women are allowed to play on an NBA team, but since female bodies are so different from male bodies, there aren't any women who can play basketball on that level. The WNBA exists so that women who are good at basketball, but not as good as men, can have their own competitive league.

WWE has an Intercontinental Championship, and a Women's Intercontinental Championship. One is exclusively for women, the other is gender neutral, which means typically it's held by a man, although it has been held by a woman before.

Calling one belt the women's championship and the other one just the championship isn't sexist. That's just how sports work. That's even more clear when you're not looking at professional sports, when you're at the high school level, it's not that uncommon for a girl who is really good at wrestling to wrestle on the boys team.