I can't find a single instance of a down and locked B737 nosegear collapsing on a normal landing without first striking something. Is there one?
Here's another nose gear collapse. OAK six years ago:
Southwest flight's gear collapses on landing at Oakland airport - SFGate
Was not a "normal" landing as they had gear/hydraulic issues prior to the landing but at some point they had "three green" - indication of 3 down and locked landing gear in the cockpit - prior to landing. Nose then collapsed after touchdown.
If anyone thinks the crew in LGA had anything other than three green prior to landing they are crazy. The nose gear may very well not have been down. But I would say with 100% certainty that they were indicating down and locked in the cockpit. If not, no way they land at LGA.