  BFSS proposed that asymptotically flat M-theory is dual to a large $N$ limit
of the matrix quantum mechanics describing $N$ nonrelativistic D0-branes.
Recent insights on the soft symmetries of any quantum theory of gravity in
asymptotically flat space are applied to the BFSS matrix model. It is shown
that soft gravitons are realized by submatrices whose rank is held fixed in the
large $N$ M-theory limit, rather than the usual linear scaling with $N$ for
hard gravitons. The soft expansion is identified with the large $N$ expansion
and the soft theorem becomes a universal formula for the quantum mechanical
scattering of such submatrix excitations. This formula is shown to be the Ward
identity of large type IIA $U(1)_{RR}$ asymptotic gauge symmetry in the matrix
model, whose asymptotic boundaries are at future and past timelike infinity.
