It's pretty much guaranteed, though there are different kinds of symbiosis I suspect you specifically mean mutualism where both creatures benefit.
Small birds removes parasites from larger creatures today and there's no reason to believe this didn't happen prior to the extinction. The Jurassic World giganotosaurus teeth cleaning(probably inspired by this piece) is also very likely.
There's also symbiosis like commensialism where one creature benefits and one is not affected like this beetle that lived in dinosaur nests and fed on detached dinosaur feathers.
Not only were they involved in symbiotic relationships with others species, it seems they may have been on the brink of the first dinosaur city states!
There's a bias we have that humans are the pinnacle to evolution and if evolution makes everything better over time then shouldn't everything end up being human-like eventually?
In reality evolution just makes us adapt to the environment as it is, and to have larger energy consuming brains is not always better for survival. If it were, everything would evolve bigger brains.
Dinosaurs could have taken that step incidentally at some point in another timeline, but they were nowhere close to the traits that are necessary for maintaining a large social society.
Fair enough, I found both articles a little silly and in the latter one it seemed very much like using humans as the yardstick of evolution, especially with the anthropomorphic dinos on the article and that all the traits the dinos could have achieved in the authors imagination are human traits.
They outnumber us at the very least 10 to 1 and have a wider global distribution than humans. Don't fall for the "Birds Aren't Real" stuff, they are real, they are dinosaurs, and they are likely prepped to rise again....literally on the hot currents of air we are providing them.
The way humanity is going at the moment it doesn't seem unreasonable that our dinosaur cousins could become dominant again for a few million years at some point.
Sure, why not? It's likely that some of them did. That said, I can't think of any examples we know of off the bat for sure.
The example of birds cleaning larger animals is probably fairly close to something that could have happened, I've seen the concept floated that some small pterosaurs might have filled a similar role, picking pests off of the large herbivores.
But to actually have proof of a symbiotic relationship in prehistory would be pretty difficult I'd imagine, since that kind of behavior is hard to capture in a fossil.