This gives you an idea of how the translation looks. For those who might prefer to see the film with the original Japanese voice actors and subtitles, GKids also released a Lupin III: The First subtitled trailer. You can, for example, definitely hear what Tony Oliver sounds like as Lupin and Doug Erholtz sounds like as Zenigata. There isn’t a lot of dialogue in this first teaser, but there are still a few samples.
GKids shared its first Lupin III: The First English dub trailer. While there hasn’t been an update on a theatrical debut, what with the current state of the global pandemic, we do have an update on the English release. Back when GKids announced it would distribute Lupin III: The First outside Japan, it noted that it would have an English dub or subtitle options for its cinematic debut.