So …. it’s quasi official. Unless the dialogue gets cut between now and July 1, there’s a line in Legend of Tarzan: “They’re not gorillas, they’re mangani.” This is from an industry source who has seen the movie. There is also reference to Mangani being more aggressive than gorillas. Just for reference, this is what Burroughs says when he introduces the mangani in Tarzan of the Apes:
The tribe of anthropoids over which Kerchak ruled with an iron hand and bared fangs, numbered some six or eight families, each family consisting of an adult male with his females and their young, numbering in all some sixty or seventy apes. Kala . . . was large and powerful—a splendid, clean-limbed animal, with a round, high forehead, which denoted more intelligence than most of her kind possessed. So, also, she had a great capacity for mother love and mother sorrow. But she was still an ape, a huge, fierce, terrible beast of a species closely allied to the gorilla, yet more intelligent; which, with the strength of their cousin, made her kind the most fearsome of those awe-inspiring progenitors of man.
Knowing now that this is the intent, I took some screenshots of the ape images from the 2nd trailer. The most striking one is the first one below, which definitely looks like something other than a gorilla. It’s from the very end of the trailer and is only on screen for a few frames.