No, it is not normal at all. Usually a crew stays with their ship wherever she goes.
Depends on the costs involved with moving dependents.
There are 3200 sailors (ships company, not airwing) deployed to Japan on Washingon. Another 3200 in Norfolk on Roosevelt and yet another 3200 on Reagan in San Diego.
Keeping the crews with their ships would entail moving those 9600 sailors’ households to the ships’ new homeports. Iow logistically difficult and prohibitively expensive.
I’m just suspicious enough to wonder why three of our ships need to have crew swaps all of a sudden?
What’s around the corner that we don’t know about?
Is there a reason someone doesn’t want our crews to be at the top of their game?
The general protocol for a carrier crew used to be those with a year or less left on their enlistment took the ship to the yards for what was then a year long overhaul and those with more than a year got transferred off either right before or soon after entering the yards.
The guys with under a year to go then trained {qualifying} the new oncoming crew starting about three months before leaving the yards. But that was on conventional powered steamers. Each ship has it's own quirks, differences, and issues to learn, even those in the same class.