Been following this story for a while now. Here's my take (in case anyone actually cares)
1. Predicted by Musk as above
2. Predicted by Cliff High (Of webbot fame, has had some good hits before)
I believe we are seeing a combination of things at the moment.
A while ago there were rumors of a dirty bomb in the USA maybe during election, maybe inauguration, maybe as distraction.
More recently there were rumors of a nuke warhead delivered to Ukraine to be used as a method of escalating the war. Apparently that escalation was avoided, maybe as it became clear that Trump would likely win election and make deal with Putin. The warhead has since gone missing and is thought to have left Europe.
In desperation or perhaps through intelligence, traces were identified on the east coast, with elevated readings over new York Manhattan and surrounding area.
Nuke detecting drones were deployed to try to find the missing warhead and have been scouring the area for some time now. This explains the low flight and search patterns. There are so many of these things flying around at night that there has even been a strike against a commercial aircraft either taking off or landing not sure. This was passed off as a birdstrike, but from the footage it seems unlikely to be a bird.
That said people have been noticing some weird stuff that seems to indicate advanced tech. As mentioned above, the drones seem to have defensive capabilities. They don't appear on thermal scope, are extremely manouvreable/fast when needed, and seem to be able to disable civvy drones by disrupting battery / control method. This is reported by both private drone pilots and police pilots.
Similar defensive abilities have been observered by private drone pilots attempting to penetrate area 51. Basically you fly a drone a few feet beyond the fence and it just falls to the ground.
It would seem one drone crashed and was recovered. HASMAT deployed possibly due to the nature of the nuke sensors as well as classified tech (keep civvies away)
I don't know why the drones don't fly during the day, other than being easier to ID. They apparently look like aircraft which makes sense due to a folding wing model that apparently has the nuke sensor capability. I would think if the situation was as serious as looking for a nuke, they'd go 24/7, but there is concern about not panicking the local population.
Complicating factor:
With all the activity and buzz this is generating more people are watching the skies. There are conflicting reports on what the drones look like. Some people say low flying car size aircraft with various configurations of blinking/identification lights. Other people are reporting glowing orbs of various colour.
In my own experience I have seen what I would term UFO glowing orbs. Extremely bright orange or pink/red, hard to look at, appear to be burning. Can be very fast and make radical manouvres. My suggestion is that they are either supranational (breakaway civilization tech) or 'dem aliens. Have observed these on several different occasions in Ontario. I observed them going into the lake. People on the east coast seem to think they are either coming out of the ocean and returning there.
These orbs have often been observed at key moments in history where nuclear events were occurring. Hiroshima and Nagasaki, Chernobyl, 3 mile island, as well as other lesser known leaks / meltdowns, some nuke tests bikini atoll and upper atmosphere tests, as well as the infamous disabling of minuteman missiles in silos In Montana.
Decades after an unidentified force disabled the ICBMs he commanded at a Montana base, Robert Salas finally briefed the Pentagon on it.
calgaryherald.com
It would seem the orbs show up at events that could have major consequences for the planet and they seem interested in prevention, likely not for humanity's benefit, but for the preservation of the planet.
This is the story thus far as best as I can tell... take it for what you will....