Yes, we'll see what happens.
Look, to be as valuable as Danny while being just an average runner and defender as 2B, Rendon would have to hit roughly like Bryce Harper did last year.
If he was a below average defender, he'd have to hit like Adam LaRoche to be as valuable as Danny, and that's the more likely defensive scenario. If he was a bad defender, which is certainly possible, he'd have to hit like Albert Pujols to be as valuable as Danny.
That's assuming Danny is no better than last year, and that's just to be AS valuable as Danny, which is certainly not the threshold you want to shoot for as a GM looking to replace a popular member of your WS contending team.
People can dream on Rendon however they please. Personally, I think it's important to understand that if the front office replaced Espinosa with Rendon, they'd likely have an expectation that Rendon would be a substantially better hitter than Bryce Harper last season.
I think it's unlikely they expect that, which is why I expect to see Rendon in September to spell starters and pinch hit.