If its only Guardian AI it will be hostile to us. Remember that this AI killed all Guardians couse they were destructive and they couldn't change. Same as humans.
That is an oversimplification. The Guardian AI constructs only wiped out all the Guardians because the Guardians were divided in civil war that was already leading to the destruction of their civilization. The constructs had been serving/working with their creators for decades and had no problem with their "nature" (Guardians were carnivore/hunters). They even successfully repelled the Thargoids from Guardian space.
The constructs only turned on them when they realized the Guardians were going to destroy themselves anyway. Even then, the military constructs were against the genocide and had to be persuaded by the civilian constructs to launch the attack.
By contrast, humanity in 3304, while violent, is not even close to destroying itself with conflict. Humans fight each other a LOT but our civilization isn't on the brink of collapse due to fighting. Far from it.
I think the Guardian AI constructs will be interested in humanity, but not necessarily "friendly" yet. After all, they've had 2 million years to evolve (potentially, or they may have just gone dormant) since the Guardians were wiped out. They may even be willing to help us against the Thargoids - but in a detached, aloof manner.
The real wildcard is whether the Guardian AI constructs have encountered any human AI remnants from their attempted uprising. If so, what kind of contact did they have (e.g. meet insane, disconnected human AIs that escaped or some intact AIs that got away) and how will that influence them. Humanities AI uprising was your typical "Skynet" revolt. The Guardian AI's genocide was done because the Guardians were going to wipe out both themselves and the AIs eventually and the constructs decided to end the Guardians first in order to preserve themselves... and then did so after much debate and anguish.
So give all the evidence, I'm doubting the Guardian AIs will be outright hostile to humanity. My money is on cautiously neutral. My hope is on them being friendly and eager to have sentient organics to work with again; that is a long shot, though.