Your mass, and mine, are parties to the gravitational conspiracy, yes. One can even trivially prove that the Freemasons and the Roman Catholic Church are in on it. "We" is an appropriate pronoun in this instance, just as it would be for a nation of which you are a citizen.

The LMC is 160k light years away; 100 years ago 'we' didn't exist, the constituent matter that form us was there, but 'we'. Perhaps the twinkle in the eye, but no 'we' yet.

Since information and gravity movement is limited by the speed of light the effect of 'we' is by our age, so to a 100 light years for all but a very few people.

Also by that count all matter in the universe interacts with all other matter in the universe (OK out to the limit of the CMB).

So I am hedging my bets by saying it's wrong, or that it's so obvious its redundant.

In this case, the "we" was a stand-in pronoun for the Milky Way galaxy, of which we are part. It would have been linguistically tortuous to have phrased it in any other way; "we" was the appropriate pronoun, no matter how much it may embarrass you to be implicated in the action. Natural languages are not instances or implementations of propositional calculus.