P2 symbol constellation in DVB-T2
Ok, question solved. I found out that indeed L1 pre/post constellations are not rotated.

The constellation above comprises:


L1 pre (BPSK)
L1 post (64-QAM)
Data PLP from P2 symbol (rotated 16-QAM)


Also P2 cells are interleaved (ETSI EN 302 755 @ 8.5).