No. A change in title or duties should be reviewed for the appropriate immigration action and the rules affecting classification and stay. The existing approval should not be treated as automatically covering a materially different managerial role.
Review before the change takes effect
Provide the new duty breakdown, authority and effective date to the immigration reviewer. Prior L-1 time and the timing of any change can matter to longer-term planning. Keep family status dates in that review.
An internal promotion announcement does not itself grant a new classification or extend the employee’s authorised stay. Review the change before it takes effect, because afterwards the verification is retrospective and harder. Provide the reviewer with the new duty breakdown, the authority attaching to the role and the effective date, and ask what immigration action the change requires.
Prior time in these classifications and the timing of any change can matter to longer-term planning, so bring exact dates rather than approximate years. Keep the family status dates inside the same review, since they move on their own schedule. An internal promotion announcement grants no classification and extends nobody authorised stay, whatever the organisation has been told.
Record the effective date in writing before the announcement circulates internally. A late review costs more than an early one and settles less.