This is speculation, of course, but: there are several large Internet Exchanges in NYC, and US/EU peering points. It's probable that a fiber cut could have cut several other links, and the failover links are now completely overwhelmed.

I'm not knowledgeable enough to answer that question. However, this is the only Twitter comment that mentions this on their page, and I don't have access to a Verizon account to verify their outage status memo. We had a flurry of employees saying their connections were going haywire to the business and this is the only thing I've been able to gather outside of downdetector.

Verizon had (and apparently still has) a few vulnerable links in the NYC metro area that have wide ranging impacts.

If it's a fiber that goes into major data centers it certainly could.