What lore do you wish was included in the game?

There are a lot of pokedex entries that are weird/intimidating/creepy, but they don't appear in the game at all...
Like driftloom stealing away children...
or pokemon like Seadra or Jellicent taking down ships.
Golbat and Haunter straight up attacking people at night.

What kind of "Pokedex canon" do you want to see happen in the game?

One reason as to why these things don't happen in-game is that they would likely require additional graphics and animation development, as well as coding. Plus, if they do implement these kind of tidbits for one Pokémon, they would likely have some feeling to do same for all the rest, so that things would remain balanced and in-check.

Golbat and Haunter attacking people at night would be pretty cool, I'd imagine! Instead of encountering them straightforwardly while stepping on grass, it'd definitely be nice to see them approach you beforehand and whatnot, and fly around, pretending to attack. If they don't eventually go away, perhaps then would the battle begin?

Same goes for Pokémon such as Seadra and Jellicent; while you're surfing, you'd suddenly be jumped by them, causing you to get into a battle.

The golbat animation is certainly a cool idea.
I wasn't saying so much "Watch a child drift away!" as evidence given in-game that these things actually happen.

Like, stantler horns on display somewhere, or a rich person with a collection of Grumpig pearls and Starmie gems.
Being able to pluck the fruit from a Tropius's neck (or having it generate fruit that it will then be 'holding')
Cool little things that aren't big changes to the game's system, but more like... little easter eggs if you have a keen eye.
There are already some examples.
Pokemon like zigzagoon and Sneasle already do this - their pokedex entry say they like shiny things and stealing things, and their abilities reflect that with "Pick up" and the hidden ability "Pickpocket"

It'd be pretty awesome to see Golurk with a unique Fly animation.

The in-battle one's alright- but how great would it be to see this giant thing pick you up and rocket away whenever you needed to get somewhere?

Golurk's out-of-battle flying animation would be pretty interesting to see, definitely. Some might say that it could get repetitive after a while, but same could be applied to pretty much everything else, I believe, including our traditional flying one, as well as surfing, waterfalling, rock-climbing, and all other animations that we had chance to see before. It's not much of a big deal, if you ask me.

Though, even if it does wind up to be tiring for some, one way to possibly help prevent that is to maybe include a variety of different camera angles, each of which would be used during different flights. Plus, there would also be scenery and whatnot, which would change accordingly depending on whatever location you happen to be.

Couple of other animations I feel would be cool to see is Gyarados performing Bounce and Dodrio flying (I suppose latter would spin its head around like helicopter continuously, but it would still be pretty interesting nonetheless!).

I would also like to see Golurk with a flying animation to use in Sky Battles. It can learn fly and it was shown flying in the anime, so why not?