No. The river runs into the ocean anyway, and even if a new source of freshwater were to run into the ocean, the oceans are so massive there wouldn’t be any measurable change in salinity. A canal like this probably won’t have much flow anyway, as it’s meant for shipping and transportation rather than water diversion or irrigation.
The article does note some concerns in terms of additional pollution and disruption of wildlife due to increased traffic and more industry.
That’s just how US people are raised.