What happens to unique_ptr after std::move()?

No, you cannot do that instead. Moving the unique_ptr nulls it. If it didn’t, then it would not be unique. I am of course assuming that attachActor doesn’t do something silly like this:

attachActor(std::unique_ptr<Tony>&&) {
    // take the unique_ptr by r-value reference,
    // and then don't move from it, leaving the
    // original intact
}

Section 20.8.1 paragraph 4.

Additionally, u (the unique_ptr object) can, upon request, transfer
ownership to another unique pointer u2. Upon completion of such a
transfer, the following postconditions hold:
   — u2.p is equal to the pre-transfer u.p,
   — u.p is equal to nullptr, and
   — if the pre-transfer u.d maintained state, such state has been transferred to u2.d.