In watching that meet in full it was a mixture of very normal results mixed with a heck of a lot of huge personal bests. For example, Bol's teammate Eveline Saalberg matched her at 50.95, but obviously at 400 flat not hurdles. Bol joked to Saalberg on Instagram that they were "twinning."
Meanwhile Saalberg completely bypassed the 51s. She hadn't been under 52 in two years.
I don't understand why this meet wasn't contested earlier, when Olympic qualification window was still open. It would be the most popular small venue meet in the world.