We don’t know all the facts.
BUT- I have heard of a lot of (rumored for sure) game-playing with ED, and so I doubt this is a situation of ONE kid in the last ten years from ONE school and ONE rogue GC.
A game that seemed pretty popular for the last few years was petitioning for a Gap year to work, volunteer, become fluent in Spanish, religious mission work, etc. And then once the Gap year was approved, the kid basically spent the summer and fall “enhancing” the college application and applying “upwards”. Of course this required the help of the guidance counselor- resending the transcript, rewriting the recommendations to reflect the “maturity and leadership” the kid had allegedly gained by the Gap experience, etc.
So the kid has as his/her safety school the locked in ED school (they got the advantage of ED if there was one) while still “shopping around” with the benefit of another taking of the SAT, bogus Gap experiences, etc. and the hopes of a better ranked admissions.
I think the number of times a kid has a legitimate reason to back out of ED the colleges are beyond gracious. I know a case where a parent got a cancer diagnosis after the ED admission and the HS senior was going to be the household backstop during chemo, driving younger kids, etc. and so needed a commutable/live at home option. Not only did the college say “of course you are released from the ED obligation” they basically offered the kid a “just let us know when you are ready to enroll if you decide to take a year off, decide to take a few classes at a local U but not enroll as a full time student, whatever you and your family need”. So I think it would take egregious gameplaying over a period of time to get a negative reaction.