The following story contains a spoiler for Avengers: Infinity War. You haven't seen it yet? Seriously?
Tom Holland has built something of a reputation for himself as a guy who tends to say more than he should when it comes to the Marvel Cinematic Universe. While that reputation may be largely earned, sometimes, it isn't actually his fault. On opening night of Avengers: Infinity War Tom Holland showed up at a Los Angeles screening of the film where he thought he would be greeting an audience who had just watched the movie. So he made a reference to his character's fate that they had just witnessed. Unfortunately, he was actually supposed to be introducing the film for the crowd. The blame for this one belongs to Infinity War writer Stephen McFeely...
So, while it was absolutely Tom Holland who spoiled the fact that Spider-Man was one of many to get taken down at the end of Avengers: Infinity War, it totally wasn't his fault this time. That doesn't really absolve him of all the other times that he totally revealed information he wasn't supposed to, but if he can't trust others to give him correct information then how is he even supposed to know what he's allowed to say ever?
Stephen McFeely tells Yahoo Movies that Benedict Cumberbatch, who was also there, was absolutely mortified when Holland said it, apparently because he knew the audience hadn't seen the movie yet. Odds are that the reason Cumberbatch was even there was specifically to keep Tom Holland on a short leash. For whatever reason, he was the one apparently chosen to act as Holland's handler during press events to make sure the guy didn't spill anything.
It would be one thing if the fact that Avengers: Infinity War was finally out released some of the pressure. Unfortunately, for Tom Holland, and everybody else, there's an entire movie that has already been filmed and that's also a year away from release that everybody now has to keep quiet about.
On the plus side for Holland, while the fact that he died was a spoiler, the fact that he probably won't stay dead really isn't. We know that a sequel to Spider-Man: Homecoming is planned to come out just a few months after Avengers 4. The difficulty is that the movie will apparently have to film and market itself all without giving away major spoilers for the next Avengers movie.