  Motivated by recent reports of nematic order in twisted bilayer graphene
(TBG), we investigate the impact of the triangular moir\'e superlattice degrees
of freedom on nematicity. In TBG, the nematic order parameter is not
Ising-like, as it is the case in tetragonal crystals, but has a 3-state Potts
character related to the threefold rotational symmetry ($C_{3z}$) of the
moir\'e superlattice. We find that even in the presence of static strain that
explicitly breaks the $C_{3z}$ symmetry, the system can still undergo a
nematic-flop phase transition that spontaneously breaks in-plane twofold
rotations. Moreover, elastic fluctuations, manifested as acoustic phonons,
mediate a nemato-orbital coupling that ties the orientation of the nematic
director to certain soft directions in momentum space, rendering the
Potts-nematic transition mean-field and first-order. In contrast to the case of
rigid crystals, the Fermi-surface hot-spots associated with these soft
directions are maximally coupled to the low-energy nematic fluctuations in the
case of the moir\'e superlattice.
