It's a real word. And used correctly in context so unlikely to be a typo.

https://www.dictionary.com/browse/backronym

https://www.wordnik.com/words/backronym

Acronyms were very rare prior to about mid 20thC.

A number of words sound like they should be an acronym or people searching for an explanation of them make backronyms out of them.

Posh and rap being turned into acronyms as per the first like are good examples of a backronym.