Is it just me, or does anyone else who sees temperatures in degrees Fahrenheit (without a Celsius conversion) in a summary of a scientific report like this just automatically consider it an American fluff piece and click-bait to be ignored?

You should read the actual report https://www.science.org/doi/10.1126/sciadv.adk1189.

It might be my naive reading, but it seems that flooding the ocean with 4-5% of the gulf stream flow with fresh water from glacier melt (I think that's a lot) will cause a shut down in the year 3700 or so. Even I, as a climate change believer, think that's a little too far out there to be considered germane.