While Gearbox have been a bit weird with regards to Borderlands 3, first announcing it only to say that they actually didn't, it has been confirmed that work has commenced, although we have yet to see anything concrete from the project. However, it looks like the studio may soon be able to tell us more, as a new rumour suggests it will release sooner rather than later.
The YouTube channel Triple S League claims to have heard from two independent sources - both involved in the project - that localisation work has begun on Borderlands 3, and that several languages are being processed at the moment. Actually, this has been going on for the past few months.
Localisation is usually among the final steps in development, and happens after all the content is locked down and completed, with only optimisation and bug crunching being left. Of course there's no way of independently verifying the report, so do take it with a grain of salt, but the channel owner does mention that the game is on track for a release in 2019, or in fiscal year 2020 (according to Take-Two Strauss Zelnick) which stretches from April 2019 and all throughout the year.
Have you been eagerly awaiting Borderlands 3?