The retcons are dramatically pretty nifty...
the claim that they had no interest in people, only machines
And doesn't that
put the heroes in their place! "Sure, they are interested in people. They just aren't the slightest bit interested in you
the idea that drones were incubated from birth rather than assimilated
It's really enjoyable when our heroes on occasion make completely incorrect guesses about alien species, isn't it?
We accept that Data doesn't use contractions
What an odd thing to "accept" when it doesn't even exist! Data keeps using contractions throughout his known existence, and never suggests that he wouldn't. He just tends to use stilted patterns of speech, and readily admits to being wooden in other ways as well.
We accept that Khan and his people were created by genetic engineering as stated in TWOK even though the original episode said they were created by selective breeding.
Another fine example of nothing really being contradicted, because one is the other, just in somewhat different terms. Far more clever than Obi-Wan claiming that "your father was betrayed and killed by Darth Vader" was a "certain point of view"... (But that works just fine, too.)
We accept that Picard is an expert in archaeology even though "The Last Outpost" portrayed a Picard who 1) knew nothing about the subject and 2) had never heard of the ancient Tkon Empire.
is established. But 1)
doesn't follow. Schliemann had never heard of Tikal and knew nothing concrete of Mohenjo Daro, but was a halfway credible amateur archaeologist nevertheless. Nobody
from Schliemann's days had heard of (or, made) the all-important migration pattern discoveries relating to the settlement of the Americas by early man.
in 2364 knew about the Tkon isn't unclear. Whether the knowledge about them amounted to anything solid or relevant is open to debate, though. Schliemann thought he knew a thing or two about the history of Troy and the ancient Greeks, but he was dead wrong. What archived stories of the Tkon Data was able to access may have been 100% false, too - except it now turned out they weren't. For all we know, Data is having a Daniel Jackson moment here, associating implausible legend with fantastically revealed fact...
Picard being a renaissance man was well established at that point already. His specific credentials in archaeology are open to speculation; his not knowing about the Tkon is not a detour from his character development, any more than his ignorance of certain recent engineering feats is in contradiction with his general grasp of physics.