If your going by the number of new cases today, you can’t really conclude a dramatic drop. Worldometer posts data as it is received so today’s total is incomplete. Keep checking back until 8PM EDT for more updates. The current day ends then (Midnight GMT)
This is not to say that there aren't new cases and these new cases won't cause new cases, but there was a dramatic shift in many areas to adjust and heightened anti-viral practices in many states starting on March 13th or so. That's 10 days ago. However the impact of these changes influence the cohort after the current one who have access to immediate family members and their own tighter social circles.. so the secondaries continue for another two rounds at least 15 - 22 days.
New York is special because folks just didn't take this seriously and because of the massive connections to other countries through New York's diverse population and connections to international trade. Just like Congress members.. there are people who do "meeting people" and this is a big deal in New York.
I agree.. it is still fluid.. but I have watch this for a few days and now I am kind of getting a feel for their updating. But, the testing is driving what I call surges.. as new testing comes on line.. This is what happened last week as Drive through testing got in place in many locations in the hardest hit cities last Friday which drove a spike of results into the numbers.
The huge hole in understanding this is caused by the lack of good old random sample population testing to get a percent penetration number and a growth rate number that is population based rather than symptom based.