In Hicks v. Berryhill the 6th Circuit Court of Appeals held unconstitutional the process that the Social Security Administration had used to terminate the disability benefits of hundreds of former clients of Eric Conn, who was found guilty of fraudulent conduct. That opinion came out on November 21, 2018. After getting two extensions, the Social Security Administration asked for rehearing en banc on February 6, 2019.
Normally, cases at the Court of Appeals level are heard by three judge panels. However, after an opinion from a three judge panel, the losing party can ask that all the judges on the Court hear the case en banc. The 6th Circuit has 16 judges. En banc review is seldom requested and rarely granted.
An oral argument is very much an interactive process. I can't even imagine what it would be like to argue a case before a 16 judge panel.
If this is reheard en banc, I fear that the result will be a deeply fractured plurality opinion, one where there's not a majority of the Court in agreement on anything. A plurality opinion would probably leave the Social Security Administration uncertain of what it should do. Plurality opinions are bad enough when they happen at the Supreme Court. They shouldn't happen at a Court of Appeals.