Update: It has since been clarified that the Legend of Zelda: Breath of the Wild 2 voice actors were joking when they said they were almost finished recording dialogue.
What the actors said was taken out of context due to a lapse in translation - at present, it's unclear how far The Legend of Zelda: Breath of the Wild 2 is into development.
Original story: It looks like The Legend of Zelda: Breath of the Wild 2 is closer than we thought.
The voice actors behind the Spanish dubs of Zelda and Revali in The Legend of Zelda: Breath of the Wild, and its upcoming sequel, have revealed that they're done recording lines for the sequel.
Seeing as the Spanish dub is done, according to the actors, it stands to reason that the English story is also finished. While this doesn't tell us how far away Breath of the Wild 2's release is, it indicates that the game is closer to release than many would have suspected, as localisation typically falls towards the end of a production schedule. It also confirms that Revali will show up again in the sequel.
It's worth keeping in mind that The Legend of Zelda games don't usually have a tonne of spoken dialogue, so this could be an indication of the volume of work rather than how far along it is.
Breath of the Wild 2 was announced at E3 2019. Since then, Nintendo never mentioned it in subsequent Directs, or showed off any footage in any official capacity.
In an interview following its reveal, producer Eiji Aonuma said the sequel will be darker, taking inspiration from Red Dead Redemption 2, where its predecessor took inspiration from Skyrim.
Nintendo has not shared plans of an E3-style event this year, but Breath of the Wild 2 could still get its own Direct later this year.