The race organizers really fucked that one up. But women catching the back of the men’s peloton is a “problem” that happens from time to time, and it can be hard to tell when it’s incidental or intentional strategy. It has been a tactic for some women to push extra hard at the start to try and catch the men’s field to draft behind them until the finish, which is an unfair advantage. Which is explicitly illegal in most racing series.
Though that gets complicated when it’s a woman catching a large men’s peloton that the female rider can’t ride alongside, and would have to just ride awkwardly far behind the pack to avoid running afoul of the rules.
I don’t know the details of this race in particular, but it seems the organizers halted the race to avoid this once they realized they really should have started the women’s race later. Was she intentionally trying to catch the men’s group? Maybe. Starting a breakaway from 2km in is almost certainly unsustainable, so if she wasn’t planning on catching the men’s field, it was either gross overconfidence or terrible strategy. She was very likely going to get caught by the women’s peloton regardless, and passed since they’ll be on fresher legs when they do catch her.
Edit: I should add that stopping the race for a few minutes with a neutralized restart is not entirely uncommon in pro cycling. For example, if part of the field has to stop and wait for a passing train, they’ll stop the front of the race as well, and restart them with the approximate gaps between groups they had before the train.