Was my unit taken off rent stabilization correctly?

[fortunecookie]

My current lease started in Feb 2023 and was for a rent stabilized unit. I am discussing renewal now and the management company says they deregulated the market rate units in the building from the 421-a(16) program. I don't recall receiving a notice this happened, but they claimed they filed the paper work on June 16.

Here's a more detailed chronology
- Feb 8, 2023: I signed a 1 year lease for a rent stabilized unit
- Feb 15: Lease begins
- June 16: Management company submitted "NOTICE OF 421-a (16) APARTMENT MARKET RATE THRESHOLD EXEMPTION - 2023" (link: https://hcr.ny.gov/system/files/documen ... able_1.pdf) to take my unit off rent stabilization. DHCR records show apartment status as "Permanently Exempt" starting this date.
- Dec 5: They notify me the unit is no longer rent stabilized during lease renewal discussions
- Feb 14, 2024: Last day of lease

Other information

When I signed the lease there was a rider talking about 421-a rent stabilization. From the first part of the rider: https://imgur.com/a/Qri5M0B

I requested my unit's rent history from DHCR and see that the apartment status was listed as "Permanently Exempt" starting June 16, 2023, but it also doesn't have any information about my lease that started on Feb 15. The next closest lease ended mid Nov 2022 - this means there was a 3 month gap between the end of the previous lease and the start of mine.

My building's status is "421-A (1-15)" on DHCR's list of 421-a buildings in Manhattan from 2022 (link: https://rentguidelinesboard.cityofnewyo ... hattan.pdf). I can't find the same list for 2023, but the 421a Exemption page shows my building as exempt (link: https://www.nyc.gov/site/finance/benefi ... -421a.page).

The "NOTICE OF 421-a (16) APARTMENT MARKET RATE THRESHOLD EXEMPTION - 2023" (link: https://rentguidelinesboard.cityofnewyo ... hattan.pdf) management sent me did not include a signature/date, but I'm also not sure this is what they submit to the government for deregulation. The notice also states this is for 421-a (16), which is not the same status as DHCR.

Generally I'm confused about the status of whether my unit is rent stabilized. Does it look like it's actually deregulated and did they do this correctly?