There are some exos races we know precious little about. We know the rumour of them or suspect of their existence, we might even know the name of their race but we have not, to the best of our knowledge, met them.
In distant history there are legends of creatures from the stars visiting Gaia, just as Kalshodar have created similar myths on primative planets. We have myths of creatures that might, indeed, be exos races.
The trouble is, we simply do not know if these races, should they exist, are our friends or not