I was thinking about how the monicker 'A' is used by Archie Waters and now in ways by Bloody Rose.
And with the introduction of Spooky Spaghetti, a very mid-2000s internet era concept, it stands to reason that the concept of 'A' was circulating as an urban legend from Rosewood.
That could be a reason that Clanton and Archie took on that title. They heard of Charlotte, Alex, and Mona's crimes as 'A'.
THEN I was thinking about how there is no way Mona doesn't know about this shit happening in Millwood. Like she still has Alex and Mary Drake trapped in her dollhouse. She is still playing the game.
So my headcanon is that Mona DESPISES 'A' being used under these circumstances. Like, Mona loved the game, never the violence. While she killed, she was not gory or psychotic in the way Archie and Bloody Rose were and are.
So Mona is keeping tabs on this and is just so pissed that this is happening.