This doesn't seem entirely new, since they are just strengthening existing warnings about NSAIDs, but it still seems like it could be a big deal.
FDA Drug Safety Communication: FDA strengthens warning that non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) can cause heart attacks or strokes
I didn't see a mechanism mentioned, but I found this article 2012 suggesting one:
NSAIDs and Cardiovascular Risk Explained, According to Studies from the Perelman School of Medicine
Yea there are multiple mechanisms purported and it's definitely something to consider as a risk factor after going through all the heavy hitters, e.g. smoking, poor BP control, dyslipidemia, etc.