You gave up your entire law license(s)? Or just the states you no longer worked in?
Isn’t it true that you can optionally give up your license before it is taken away from you for cause?
Law licenses are issued on a state-by-state basis. I retained my license in the state where I still do legal work. I really don't need it anymore because I do most of my work in-house rather than for outside clients. Fortunately, that state does not have continuing education requirements and the annual fees are fairly minimal. If I had to do significant continuing education each year, which is expensive and time-consuming, I would probably let it go.
There are situations where attorneys voluntarily surrender their licenses under threat of suspension or revocation. In those cases, a grievance against them would first have been filed with the state bar association or the state court, whichever is in charge of regulating lawyers in that state. In cases where the attorney knows he or she faces suspension or disbarment they will have the option of surrendering the license rather than challenging the proceeding. Attorney grievance proceedings are matters of public record like court cases.