As far as I know it has been communicated that better looking shore lines and water masks will be implemented later.
Those trailers were shot intentionally with special/no water masks for the marketing.
That being said, as a consumer you should not accept misleading marketing. There are laws for that. Federal law states the advertising must be truthful and not misleading. As an example you are not allowed to show a product and claim it is the same as you will get, and then deliver another - unless specified (thats usually where you have the tiny text and watermarks saying "bla bla might deviate from the final release…)
Personally, I dont really care too much - as I think the sim looks great either way. But It sure was a disappoinment flying over tropical shorelines after seing them in the trailers. For a game that relies heavily on the graphics, it was definately a ‘interesting’ move.