I know that millennials are trending to living in more urban environments, but I wonder if this is a regional trend. Like are millennials on the east and west coasts more likely to live in urban environments, where the Midwest, Southwest, and Southeast are maintaining traditional purchasing decisions? I am a millennial myself, but on the older side of the spectrum.
But I can agree with eating at non-chain restaurants. I personally will eat at them, but will often look for a local place to eat. If My girlfriend and I go out, it is almost always an independent restaurant. I think my generation is always looking to try something new and explore new experiences as opposed to repeating old ones.
I think urban living is more of a testament to a city's attempt to re-invigorate their urban areas than anything tied to a certain generation. Here in KC, the options for living downtown were terrible when I first moved here 20 years ago. Now, with P&L, a decent grocery store, reconditioned buildings, lofts, etc, it's much more appealing. I would definitely have looked into living downtown had those options been here (and if I could have afforded them!)
That being said, once these same millennials get older, marry, and have kids, you'll likely see them migrate to a more laid back atmosphere in suburbia so the next wave of 20-somethings can take over. And they'll take their kids to the same restaurants they are familiar with because they don't want to fight their kids to get them to eat something new.
As far as chain restaurants mentioned in the OP, I think the market got saturated with them and the ones that knew their niche have been able to survive while others did not. Applebees got comfortable being one of the leaders and didn't respond well when other places started taking a bite into their market share. I don't think it has one single thing with one generation being more open to trying something new. Every generation feels that way.