Nintendo released their 2nd quarter earnings release today, and as is usual with these releases, the publisher posted a schedule of upcoming games planned for Nintendo Switch and Nintendo 3DS.
On page 7 of the Supplementary Information document, within the list of upcoming first-party releases, Nintendo lists Dragon Quest Builders 2 for release on Nintendo Switch in 2019 in the United States and Europe. The is the first confirmation of a localized release of any sort for the building RPG.
The original Dragon Quest Builders was published in the west by Square Enix in 2016 for PlayStation 4 and PlayStation Vita, with a Nintendo-published Switch release following earlier this year. It's likely that Nintendo will once again take publishing duties for Dragon Quest Builders 2 on Switch, while Square Enix handles the PlayStation 4 release, although Square Enix has yet to officially confirm a localization for the sequel.
Dragon Quest Builders 2 for PlayStation 4 and Nintendo Switch will be released in Japan on December 20, 2018.