It’s not the ultimate direction of the causeway that would be of any importance.
I know that you do not place much importance on the causeway but it must be considered.
But first, let's consider the N/S boat pits. They may be orientated that way because of the pyramid, but not necessarily. They may respect what is commonly referred to as the Mortuary Temple.
Light on origin?
Secondly, the most easterly boat pit is at the same angle as the causeway but does not, but almost does, encroach upon it. Therefore, this pit was either excavated first and the causeway respects it, or, the causeway was constructed first and the boat pit respects it.
Either way, the causeway is of significance.
The Polynesian angle can be supported by the correlation of Easter Island glyphs with Indus Valley glyphs. As well, the reed boats of Lake Titicaca are very similar to those of the Nile River.
A different world landscape?
The fact that the boat pits of real consequence at the GP are rectangular and face true E/W and were only recently discovered leads me to think that if anyone wished to research boat pits at Giza, then these would be a starting point.