fetching data before or after changing mobile app route

I need to change from route A to route B in a mobile app. Route B requires new data to be fetched. My question is quite simple: Are there studies that show whether mobile app users prefer / expect apps to 1) send users to the new route and wait there while the data loads, or 2) stay on the current route and then display the second route when all the data has loaded?

My hunch is users prefer the former (this is much closer to the "progressive rendering" philosophy of modern single page apps), but I'm wondering if there is empiric research that supports this claim. Any pointers others can offer on research in this area would be helpful!