Because I seem to have been one of the few people who heard the specific wording of Josh's live announcement, which said "next year we're bringing back the Happily Ever After Anthem". That's such a weird and specific way to word that announcement, and it implies that it's the only part of the show that's actually returning. Which is fine, but let's be accurate about what's happening.
The simplest theory here is actually that he would never have said that the way he did if it would have been just as true to say "Happily Ever After, the show, will be returning with updates" . The emphasis was fully on the song, but it got drowned out by a screaming crowd who assumed they understood what he was saying before he finished his sentence.
That multiple Disney-direct sources are now wording their follow ups the same way, with the emphasis on the song, seems like something we should give weight to.