As I'm sure you know, under one rather unlikely set of circumstances you can already cross the lake without the EA closing cutscene triggering, but the destination is unfinished, so it is a matter of curiosity only.
The destination ( which you see in the cutscene ) is mostly finished, and I had the impression that at one point Larian probably expected to include it in the initial EA before cutting it. So I would not be surprised to find that location included in a patch fairly soon.
