It depends on the alteration. If your current cancellation policy is still "strict", it will apply again on the alteration. But if the check-in date is moved to the future (so there going to be more then 7 days remaining before check-in date), be aware of tricks to get a 50% refund.
Accepting a guest's request to alter a reservation doesn't re-start the cancellation period. This would happen if a host submits an alteration request. Here is an excerpt from the policy for guest alteration requests,
"Note: Changes made to an existing reservation are subject to your listing’s cancellation policy. You should never make changes on behalf of your guest."