The more I think about it, the more sense it would make. Moira may have contacted Logan in secret to use it as a secret weapon if at some point she cannot trust something with Xavier, Magneto or Apocalypse.
He is old enough to have been recruited at a very early part of the plan (not like Scott or Ororo for example), she can trust him for the cause and having had so many erased memories, Xavier could not discover the plan.
Don't you think that with the thousand years they lived together in the sixth life Moira should know almost everything about Logan's past? Moira can tell Logan things that only someone who knew him could know.. It is possible that she contacted him even before Xavier.