No. There has certainly been a rejection of Labour. How much that constitutes aspecific rejection of the 'Maori Caucus' is arguable, since despite the Right's vigorous attempt to dogwhistle the racist elements in NZ society, parties with policies friendly to Maori still got more than 45% of the votes cast.
I think that the success of TPM in the Maori seats is most likely to be an accurate reflection of the sentimnt of Maori voters.