That the spouse's plans depend on status rather than sponsorship: L-2 spouses are employment-authorized incident to status. Children in L-2 may study but may not work.
Confirm the documentation, not just the rule
The rule is favourable, which is why households sometimes stop asking questions once they hear it. Two further questions are worth putting. The first is practical: what documentation will a U.S.
employer expect to see before putting the spouse on payroll, and how is that obtained in this particular case. The second is regulatory: if the spouse practises a licensed occupation, what does the destination state require, since immigration permission to work is not permission to practise. That second process regularly takes longer than everything on the principal's side, and it often involves verification sent directly from the Ontario regulator, which cannot be hurried.
A household should also ask what its plan is if the spouse's licensing takes a year, because for many families that answer determines whether the move is viable at all.