Exactly it. Vacancy filling is not the adding of additional judges to a system.
What is packing the court?
The Judicial Procedures Reform Bill of 1937 (frequently called the “court-packing plan”) was a legislative initiative proposed by U.S. President Franklin D. Roosevelt to add more justices to the U.S. Supreme Court.
Rep. Samuel B. Pettengill, (D), Indiana: A packed jury, a packed court and a stuffed ballot box are all on the same moral plane. This is more power than a good man should want or a bad man should have.