I just watched a clip of DC and Sterling talking about Francis' wrestling training. They were basically making the point that realizing you need to train your wrestling, training wrestling, and training wrestling hard enough to actually get significantly better at it are all different things. DC mentioned Izzy releasing footage of him training wrestling and BJJ, but then when he got in there with Jan, it didn't matter and he was still in over his head.
How much Francis has actually improved his wrestling, we don't know. I'd argue it doesn't matter. He's not going to be able to get that much better in 3 years against a guy that has been wrestling since he was in high school. As I said above, I think he needs to be more cautious so he doesn't give Stipe those openings to shoot for a takedown. If Stipe ends up getting ahold of that front leg, Francis is going down and it's going to be hard for him to get back up until the end of the round.
So what I'm saying I guess is it's more about how Francis approaches the fight than it is how much he improved his wrestling IMO.