"They don't wait for death saves to tick up before healing"
This is the opposite of metagaming. Metagaming is bringing in player knowledge that 1) you have to fail 3 death saves to die, and 2) bringing in player knowledge of how many death saves had been failed.
So choosing to not be as effective as possible when you have that knowledge is metagaming.
"they discuss what spells they're going to take so they don't double up"
This could be metagaming, but isn't necessarily the smart thing. Doubling up is often better, because good spells are good to have in multiple hands. Fireball is good. Two fireballs is better. Healing is good. Healing in two hands is better so you can heal the healer. And so on.
But the wizard's not taking comprehend languages because he knows that's this bard's whole thing, and he doesn't want to step on that player's fun.
"they push on in to danger instead of resting after every battle"
This is not metagaming. Resting after every fight is, because the PCs don't know about the adventuring day. That and resting can also bring encounters, so...
But the game is more fun when they don't rest constantly, so they don't do the cautious safe thing as if they're actually concerned about their lives.
"they plead earnestly with the agent of the Zhentarim they just met"
Negotiation is not metagaming.
No, obviously not. But the player who knows who Zhentarim are explicitly leaning into the fact that they will likely be betrayed because that's fun and interesting is.
"they stay committed to their course of rescuing their employer rather than abandoning him because it's only 10 gold"
Neither staying the course or abandoning him are metagaming. This is roleplay and depends on the personalities of the PCs
But choosing to do so because he's who the module is about when we agreed to play this one, is, even if you justify it in fiction after the fact.
"they don't steal from each other even though they steal from everyone else"
Same as above. Not metagaming and based on PC personality.
If you're portraying someone who is abjectly selfish and amoral, and tried to steal from the party, but retconned your actions the second the another player said they don't want to play that sort of game, it is.
Only one thing you mentioned could possibly be considered to be metagaming.
So, I disagree. All of these
can have considerations that come from non in-game knowledge. I've seen these choices play out because the players are concerned with what makes the game the best form of it, and I thoroughly appreciate that metagaming.