Hello again and thank you for your reply. Although there is no way I could say what the result would be if you filed a complaint with the City or filed suit under the law, since I don't have all of the facts from your employer's perspective, if your employer is intentionally changing the company structure to avoid having to comply with the paid sick leave law, they could be sanctioned and you would have the right to that paid leave.
In other words, under the law, as you appear to already be aware, they need only 5 employees to be subject to the law. Again, without seeing their corporate documents and knowing how the City or a court would interpret them, I can't say with certainty you would prevail, but it is worth pursuing. Your employer cannot lawfully terminate you for asserting your rights under the paid sick leave law. If they did discipline or terminate you, then you would have a wrongful termination claim against them.
If you have not already read all of the information at the Department of Consumer Affairs site on the law and how to file a complaint, you can find it at the following link: http://www1.nyc.gov/site/dca/about/paid-sick-leave-law.page
Please keep in mind, this is not a paid vacation law, only sick leave, unless the employer lumps all leave together in the form of PTO. They they must offer at least the same number of days as required under the sick leave law.
Please feel free to ask for clarification if needed. Thank you