No, this is actually a terrible thing in the long run for one simple reason: fisheries are being destroyed everywhere [1], and the US is the only nation currently with the clout to really push to change this. But since seafood isn't even on most Americans' radar and we live in a democracy, it's very unlikely any politician will ever spend political capital on it.
Fisheries are being destroyed is because blue water fisheries are a commons -- no nations own them, so whoever vacuums up the fish first reap the profits. Not to mention global warming and ocean acidification are stressing fish breeding grounds worldwide.
This model made sense up until WW2, and was in line with how international waters were historically governed, but it is an ecological disaster in the making because technological developments during the war (sonar, deep sea nets, etc.) allowed huge fishing fleets to completely destroy blue water fishing grounds.
The only way to change this is for someone to push at the international level to rewrite the agreements on fisheries (restrict them by quotas, manage them by an international body with an eye towards conservation, etc.), and the only superpower that has the political capital to really get the ball rolling is the US.
But most Americans don't eat much seafood so it's not on anyone's radar. Enjoy your seafood while you still can. Maybe rich nations will have farmed fish or domestic freshwater sources, but cheap seafood from the ocean will basically not exist within a few decades.
[1] https://www.theguardian.com/environment/2016/jul/07/global-f...