Both DWDS and wiktionary seem to be missing the use "sich aus etwas verabschieden" that is not comprised in any of the meanings they list.
"Sich aus etwas verabschieden" is mostly used in a figurative sense, which means that it's not about saying goodbye as much as about leaving something or giving up on something, where "etwas" is most often a circle of people or a group (of people, organisations, countries ...), but it can also be a contract or something similar that defines a group.
Er hat sich aus unserem Verein verabschiedet.
means he doesn't attend our meetings any more and isn't an (active) member of the club any more.
Er verabschiedete sich von unserem Verein.
can also just mean that he says goodbye, e.g. for the day or for an absence.
More examples:
Die USA werden sich nächstes Jahr aus dem Pariser Klimaabkommen verabschieden. (This means they will leave the climate accord.)
Großbritannien hat sich aus der EU verabschiedet.
Du hast dich aus unserer Freundschaft doch längst verabschiedet!
Note that verabschieden is quite often used in this figurative sense, even with von:
Die Regierung hat sich von ihren Sparvorsätzen für dieses Jahr schon im Mai verabschiedet.