"Model 3 interior is now 100% leather-free"
The departure from leather has started in 2017 when leather seating options for Model S/Model X were removed. Only the steering wheel remained leather-wrapped, but it could be synthetic upon request in the S/X. The Model 3 didn't have that option, so it becomes 100% leather-free just now.
Tesla Model Y also will be 100% leather-free inside.
In general, it makes a lot of sense to offer a leather-free interior in an electric car, which is supposed to be environmentally friendly. Big pros for Tesla for being on top of this.