I'm not good at keeping up with the current developments, so I'm not sure if they've finalized a layout for the land or if we only have speculation at this point, but if there are going to be any alternate paths/entrances to SWL other than behind BTMRR, I expect they'll have to block off the general area at some point to construct the those entrances. But off the top of my head, I can't think of any rides that would be affected by that, and it probably wouldn't be for a while.
I also don't think a lot is closed now, but I guess it seems like a lot when you list it out or if you have a nostalgic attachment to one of the close rides. I was concerned about the river being drained because it would impact such a big area of the park, but since they managed to avoid that for the time being, I'm pleasantly surprised by the low impact of this construction.