Kong: Skull Island is more than just a reboot starring the giant ape who has been a pop culture staple since the early 1930s. It's also the second tale set within the universe that's now officially known as MonsterVerse, where Godzilla also resides. Other than the scientific organization Monarch being mentioned in marketing, Kong: Skull Island hasn't provided any direct connections to Godzilla, but one of the commercials currently airing shows a subtle reference to the giant fire-breathing reptile, specifically humanity's encounter with it halfway through the 20th century.
In one of the new Kong: Skull Island TV spots, titled "Reign," John Goodman's character, Bill Randa, is heard talking about how many ships and planes have gone missing over Skull Island. He then segues into stating about how nuclear tests conducted in 1954 were actually trying to kill something. To the casual viewer watching this commercial on TV or online, this may sound Randa is saying that those bombs were dropped to kill King Kong. However, this is actually an indirect reference to 2014's Godzilla, which began with an opening montage showing the beast being bombed off the coast that same year. Which, in reality, was the year the first Godzilla movie was released in Japan. You can watch the Godzilla montage below if you need a refresher.
Trailers and other previews for major blockbusters are notorious for being edited in ways to make two unrelated scenes look connected. In this case, King Kong is meant to be framed as the target of those nuclear detonations in the 1950s, when it was actually Godzilla. However, it sounds like Bill Randa, a government official, isn't in the know about what went down in 1954, and with all the disappearances around Skull Island, he wants to head out into the Pacific to figure out what's going on. That's why he's put that expedition team together, which includes Tom Hiddleston's Captain James Conrad, Samuel L. Jackson's Packard, Brie Larson as Weaver and more. Once there, they'll see what kind of monsters live in this uncharted territory.
Kong: Skull Island takes place in the early 1970s, and it will be another four decades until Godzilla clashes with the MUTOs in San Francisco, so it's extremely unlikely that Godzilla will make a surprise cameo appearance in the movie. As for King Kong, whatever happens in Kong: Skull Island, it's already guaranteed the eponymous ape will make it out alive, as he's scheduled to clash with Godzilla in 2020's Godzilla vs. Kong.
Kong: Skull Island will wreak havoc in theaters on March 24, while Godzilla will return on March 22, 2019 for Godzilla: King of Monsters.