Apart from anything else, the animals who follow them would do vandalism to the Etihad on an epic scale. So no, for that reason alone.
A lot of their fans seem to think our ground belongs to Manchester City Council, and therefore it's not in our power to refuse. I think they have an inadequate grasp of City's tenancy rights, which are not far off that of ownership.
The obvious thing would be for them to play at Croke Park, Dublin, or Wembley. either of which would be handy for most of their fans. There is nowhere in the NW as both our gaff and Anfield are unthinkable, and Goodison Park is too small and dilapidated. Everywhere else is way too small. I suppose Hillsborough might be an option.