I don't think this explains understaffing though.

"The lawsuit doesn’t allege incompetent controllers were hired instead of CTI graduates. Instead, it states that the CTI graduates weren’t given the opportunity to demonstrate their competency."

It sounds like they hired different people, rather than fewer.

Not a pilot or a controller, just a nerd. My take from reading about it was that a large number of high performing potential ATC controllers who had followed the traditional pipeline were ditched. Ofc it's possible they hired exactly as many ppl as they would have otherwise, but in any job with a long lead time for training, a sudden change in the pipeline is going to cause ripples further on for years to come. Maybe the ppl they did hire had a higher attrition rate so that while they had the same # of ppl in the short term, in the long term, they faced shortages. Maybe some % of those they did hire required some % of extra supervision or training. Ofc not insurmountable or fatal, it just means extra pressure that will exert itself in some fashion for years to come after the initial disruption. I have no idea of last night's incident could be considered downstream of the testing change, I was just responding to the allegation that it was a conspiracy theory, however I also don't think it's implausible that it contributed to it in some indirect way.