A popular data miner Yan2295 recently posted a letter from Leah Sokolowsky, a location manager. The letter is a request to some client for the study of locations in South Florida.
It states that a group of 4-6 researchers and developers from Rockstar Games wants to come to Florida in October (presumably 2019 or earlier) to scout locations for their video games.
The scout team's mission is to tour and photograph interesting locations throughout the state of Florida. The material they gather will be used to inspire Rockstar's developers to build environments in their games. The team is primarily interested in scouting interior spaces. This may imply that we will be seeing much more interesting interiors in GTA 6 than before.
It is worth noting that such trips are quite a common practice for many game developers. Of course, it's impossible to prove this letter is legit or determine the date of writing. However, according to Yan2295, Leah Sokolowsky, the location manager mentioned in the letter, is a real person. And not so long ago Sokolowsky participated in the Film Florida podcast where she claimed to be working together with some major media company. Here is a quote from the podcast:
Recently as you're aware we've had a change in the types of productions that are coming to our state. So I've also been very fortunate to get a large client that has hired me to arrange basically site tours and visits. It's a digital media company. And I've signed an NDA so I can't disclose who it is. But they've been exploring various areas of our state, and of other states in the south east. And I've been planning and arranging those visits for their personnel and that's been kind of a very interesting expansion of what I normally do, as well.
As you can see, her words perfectly fit the letter. Apparently, Rockstar visited Florida to collect material for their future project, presumably GTA 6. There is, of course, a slight chance that someone listened to the podcast and created a fake letter. Let's hope not.