By that definition, literally every game in history is a role-playing game. You know what I mean when I say roleplaying.
We know we are going to Andromeda for *insert plot reasons here*. That's enough. It's not like our background will matter much since anything connected to our past will be 2,538,000 light years away.
You're right in that statement: most every game could be a role-playing game by what I said prior, though some are clearly more open for exploration on the part of the player, especially those with a large amount of story and lore, and whose playable character/s (if any) are without a name and voice or next to no background. That is both the horror and wonder of the human imagination: Fan-Fiction.
I cannot say I know what you mean when you say role-playing unless you mean, in the strictest of definitions: the act of playing the part or role that is given to you. Nor do I care, honestly. When I'm given the option to come up with a role for myself in a game, even if its just a fun little story in my head, I'll most likely do so. If I'm given a role in a game, I'll play that too within the rules that it gives me.
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But we don't know the uniformity, if any, of how they all got there. It could be separate, it could be different. They could all live away from one another or in a close-multiracial/species society. Some may have separated and lost contact with others, yadda yadda. We do not know.