My thoughts on consequences (some spoilers)
Naval--the Germans have lost lost of their fleet, but this will have minimal long term material results, it's probably going to be obsolete soon enough. The new leadership seems likely to focus on the land side of things--which will remove Britain's greatest concern with Germany.
The navy is discredited, with much of its experianced crews at the bottom of the Atlantic, and its morale must likely broken
The USA has more practical experinace with modern naval warfarew than anyone else does--and a Congress willing to vote for a strong defence. With the lessons of the battles off New York, I'd expect the first dreadnought type ships to be ordered within a year,,and without the displacement limits that a stingy Congress put on the USA in OTL, allowing for a better vessel.
Great Britian probably follows shortly, and the dreadnoughts start to show up worldwide.
Germany builds a few--mainly to show she's still a great power--but not the massive building program of OTL.
Army
The US army and the German army will be looking for ways to deal with machine guns in fixed emplacements. The US suffered worse in its assault on the German fortifications, and will be looking for a way to deal with that. In addition, the US army is now open to innovations--I expect tanks before too long.
Nothing makes an army look at itself like a defeat--but will the German army see it that way, or as a disaster created by the navy? This will be critical in seeing what happens next. In the book, the soldiers were blaming the navy for a lot of what happened.
Look for big land based artillery to become popular, since it was used to good effect around New York.
Marines:
The US Marines got some practical experinace in amphibious assaults. Theuy worked, but I'd expect them to work on refineing the tactics. The World War II landing craft is not technically advanced, it could be built in 1912 if someone sees a need, and designs it.
Politics:
I'd expect that Germany is paying reparations to the USA for the destruction of Brooklyn, or (more likely)had to give up the Pacific islands and Tsingtao. The US could take them easily, so the new governemnt would probably trade them away.
This makes Japan uneasy--the US is coming in force to the Pacific--bases at Cavite, and new islands to replace the newly independent Phillipines. I'd bet they will be fortified. Japan is also seeing that Britian no longer needs Japan to balance the High Seas Fleet-and is on very good terms with the USA. If I were Japanese, I'd be getting worried.
Britain no longer has to worry about Europe for a few years, and the Anglo-American alliance will make anyine thinking of starting trouble think. After all, the USA beat the invincible German Army--what else can it do? No one will leave the US out of its plans in the future--and when they add up the production capacity of the US, they will get worried.
Just a few rough thoughs