Seatmaps really are no indicator of load (on US carriers they are at least a form of a lower bound but on Euro and Asian carriers not). And yes, the business cabins will be oversold too.

The single window seats are usually blocked anyway, some will be tentatively blocked for crew rest, and some for bassinets. You could call but a glitch excluded, LX does normally not block seats for fun as e.g. SQ does.

And given how nice the hardware is, a completely full or more than full load is not surprising.