Nintendo got a real life CMOA when Universal prosecuted over copyright infringement of King Kong. They wanted to take down the games company, and saw demanding royalties and Donkey Kong pulled from the market would do it. Nintendo agreed to help and conducted research into the case, before the head honchos met. Nintendo offered partnership. Universal refused, certain the Japanese based company would crack. Then Nintendo dropped the bombshell that Universal were themselves be guilty of copyright under the legal brief they handed down (the Kong license is actually free domain) and counter sued for damages, proving once and for all they would be the heavyweights in the gaming and entertainment industry.
In Super Mario Odyssey, The reveal trailer begins in a Mario universe version of New York City. What is notable is that the mayor is Pauline, and there's multiple shout-outs to Donkey Kong, including the infamously bad scaffolding, finally bringing Donkey Kong's back story into the main canon of the Super Mario series!
Even with the above being true, it's hard not to give Mario's old nemesis some credit for being one of many Breakout Characters in the series. Granted, it's the grandson of the original, but it's something else to see the ape go from chucking barrels down buildings to braving an entire island to beat up anthropomorphic crocodiles. Some even consider the Donkey Kong Country games to be among the best on the SNES, even surpassing Super Mario World in some eyes.