Go to any stock art site like istockphoto.com and look for retro signs. There are literally thousands of them, vectored, ready to use. Buy them with an extended license and you can print all you want. I doubt that's what's going on with the signs OP is seeing though. They are either getting the standard license, making and selling as many signs as they can until they are caught, then moving on to the next design or they are just taking a basic design, reproducing the style and caling it new.
looked for "sao paulo houses aerial" on istockphoto.com then used these 1 2 photos from the same series to find the pool, the second photo has a football field which was easy to find in sat view
Today, Gotcha (the scooter company replacing Bird and Lime in Raleigh) posted this picture on their website. It's not actually Raleigh's skyline, but appears Gotcha's marketing team made a mistake since istockphoto.com does provide the image listing it as Raleigh North Carolina. So Reddit detectives, any idea what city this picture is actually from?