No, the actual time of day (vs time of clock) for accommodating cruisers won't change. The ships will still dock when they do and let the cruisers off, it's just that their clocks (if they came from the East coast) will now match the islands clocks.
The way this time zone change helps the cruise industry is that the cruisers who come from the East Coast won't have to remember not to ask locals what time it is. (Ships most of the time do not change time zones- so cruisers have to remember "ship time". And when they get really drunk, that can be hard.) The cruisers coming from Texas though are going to have to do the math themselves.
But if they get to Caleta at 900 CST now and we turn the Coz clock forward an hour to match EST, I don't have to be there until 10 right?