  In this paper, we study the relationship between the mapping class group of
an infinite-type surface and the simultaneous flip graph, a variant of the flip
graph for infinite-type surfaces defined by Fossas and Parlier. We show that
the extended mapping class group is isomorphic to a proper subgroup of the
automorphism group of the flip graph, unlike in the finite-type case. This
shows that Ivanov's metaconjecture, which states that any "sufficiently rich"
object associated to a finite-type surface has the extended mapping class group
as its automorphism group, does not extend to simultaneous flip graphs of
infinite-type surfaces.
