I really don't know why this term is thrown around in the news so much without explanation. What I thought at first (and I think is the obvious interpretation) is that with an effectiveness of 90%, 10% of vaccinated people have no protection at all.
Probably more considerations, but the above should get you started thinking of them.
J&J was 85% effective at preventing severe reactions and hospitalizations and 100% effective at preventing death. The 72%, in the US, was for mild symptoms.
There's nothing wrong with saying X is much better than Y, Y is much better than nothing.
I get from a public health standpoint you may want to blur the difference so people take the first available dose because there is a huge value to herd immunity, and a society with 100% J&J shots is going to be safer - probably even for the vaccinated given herd immunity - than 20% with mRNA shots. But I won't pretend they are equal while doing so.
Meanwhile, the 72% vs. 66% was when the world had variants not seen in the US. They're here now. I think it more likely that the vaccine has less efficacy against the variants than the vaccines have special "efficacy +" modes that are geoblocked.
I'm not sure I can envision a reasonable way to embargo the numbers.