Being assigned a role you did not pick, when the queue cannot fill your two chosen positions. Usually support.
team chat
what you type
in full english
I got autofilled support, sorry.
the context
Typed in champ select, in the past tense: "autofilled", "im filled", "autofilled sup sry". It is a way to warn before disappointing: the player does not know the role. The expected answer is "np".