The entrance plans are not currently confirmed. My personal opinion/speculation is that it will be via Timberline Drive (current WL entrance) and it will be modified to be the entrance for both WL and LSL, with LSL guests turning right on W Wilderness Road (first right past the guard house, current road that serves WDW transportation access between WL and FW). It's also possible they intend to use the current backstage service routes on Frontier Way that connects to an access road the winds behind the Stolport and make an entrance on Vista Boulevard, but there haven't been any stormwater permits or plans suggesting as such and that area is currently relatively backstage-y. A Timberline Drive/West Wilderness Way entry would be the most direct and efficient in terms of distance and utilizing existing infrastructure, in my opinion.