In 1992, DC Comics made massive public waves with a major crossover event that announced the death of Superman.
At the time, it was an unprecedented move for a comic book publisher to kill off its iconic character and spawned a gallery of replacement characters, some of whom are still active today. But of course, any modern comic fan is likely aware that this stunt didn't last forever and Superman was indeed resurrected before the decade was out.
And in the years since, enough comic characters have died and returned that the trick has essentially become old hat by now.
But since it's not quite so common for video game companies to consign their most popular (and lucrative) characters to a similar fate, it seems that some fans were given the impression that Nintendo was gearing up to pull a similar stunt for the first time.
However, it turns out that this was based on a common misreading of memes criticizing one of the company's business decisions.