>"That's all DEI was, is finding new candidate pools..."
No, it wasn't. That is what it was CLAIMED to be by those who support it. But in reality it was about giving preferential treatment to, often to fill quotas for, women and racial minorities. And when those quotas aren't met, standards are lowered to magically make more people qualify that otherwise wouldn't. Remember, the "E" in "DEI" is "Equity", which is the act of trying to force equal OUTCOMES not equal OPPORTUNITY. That is diametrically opposed to merit.
In most cases, there had been no lack of applicant supply nor qualified people to fill positions. There was a lack of positions and competition for those slots. Rather than choosing the best candidates based only merit (skills, education, experience, capability, etc), DEI was pressuring (for forcing) the consideration of factors that should not matter or be considered, like race and sex.
In relation to this article and this industry (air traffic controllers), you very much don't want to lower standards. You might want to look at the standards to make sure they are actually relevant. You might want to broaden your advertising of positions open to target different areas that might not have heard about or considered applying. But that is not DEI.