Well more than you have shown thus far obviously!
Great, it sounds like you're open to additional evidence to prove that the game treats the position on "Metagaming" as a table rule.
Not that I sure why you care. I am more talking about roleplaying in general, D&D 5e is just one of the many rule systems one can use for that.
This is a thread labeled "5e" about a situation that arose from a group playing D&D 5e, specifically a D&D 5e adventure, "Tomb of Annihilation." Since everything one needs to know about the game exists within its rules books, then we need look no further than said rules books as backup for our assertions about the game. You and Maxperson have at several places in this discussion asserted that the rules support your position on "metagaming." In fact, they do not, and they classify this as a "table rule."
DMG, page 235. In this chapter, entitled "Running the Game," the designers draw a line between the
rules of the game and
table rules for how the game is played. In the section called "Table Rules," it is suggested the DM set expectations about "Table Talk," which is (no surprise) about how players will talk at the table. One such bullet point to cover in setting these expectations is as follows:
"Decide how you feel about a player sharing information that his or her character wouldn't know or that the character is incapable of sharing as a result of being unconscious, dead, or far away."
Therefore, the D&D 5e rules specifically say that this consideration is not a rule, but a table rule, one that each group must decide for themselves. It is not a rule of the game, but rather a table rule for how the game is played given the group's preferences.
Now, I hope we can move past any further assertions that a "no metagaming" position is called for by the rules and focus on whether such a table rule is actually helpful or not.