I would say “possibly” to this, if they did it right.
In the ancient world, they were already aware of a big problem with artificial ports was that they tended to accumulate silt over time, eventually becoming non-navigable.
So they were able to design such ports so that the ocean currents would continually flush silt out of them.
However, in the case of the east coast, what they want are offshore islands that accumulate silt beyond their basic frame, and even beyond that, so it can be dredged and raise the islands a significant height above sea level.
Once above sea level, then the silt could have support members and concrete added to it to make it much more resistant to tidal surges.
... and then the rich will build homes on them & then we will have to build additional islands to protect the islands built to protect the shore...
I see a pattern here
Too stoopid for me (and my wallet)