It is not just the airlines making changes with flights.
I am cruising from Southampton to Lisbon mid October and received this email from Norwegian yesterday. (less than a month away)
"We always strive to deliver remarkable experiences for our guests, both onboard our ships and through our curated journeys to bucket-list destinations worldwide. While we truly do our best to maintain original itineraries as much as possible, unfortunately, at times modifications are made to accommodate certain circumstances. As such, due to port congestion, the itinerary has been revised as follows:"
There was time shaved off of three separate ports.
None of my excursions were affected but persons who chose to go to Paris from Le Havre may have to cancel their excursion. Equally true for those who have an excursion to Normandy.