[Does so]

...or had passed-on millions of years ago...

[Doctor DNA]

Artificial Intelligence may be inevitable for any interstellar civilization. AI equals Artificial Life.

If AI from two different civilizations make contact, what could be the possible results?

From our own AI research .... interesting results.
https://nationalinterest.org/blog/buzz/explained-artificial-intelligence-race-arms-race-119326

So there may be hope that peaceful interstellar relationships are the norm.

As the Whopper computer figured out in the movie “WarGames”: “The only winning move is not to play.”