Depends on it's application. If you were attaching it to a ventilation fan for smoke control purposes or shutdown, then at that point, the AHJ would definately be the one making the call whether he'd allow it or not. Controlling 120V from a panel comes down to the same circumstances, including isolation from voltages, etc. and whether or not your AHJ will allow it. Generally, they don't care, but when it is used for a life safety application, you bet they'll have an opinion.
NFPA does not cite any restrictions, or prohibitions of what sort of smoke detector technology to use in any application, other than suitable for purpose. The AHJ/fire marshal would probably have a strong say in what was allowed, such as PE detectors in a theater/nightclub situation, etc.
Irregardless, it means that the products, such as the relay and 120V smokes. are not listed for the application, which is being attached to a FACP. UL 268 is the one I can think of being the most appropriate. I see nowhere on Firex or Kidde where they carry that listing, without trying to get a CSR to answer that question. Compare that to any LV detector with the listings cited specifically.
120V being controlled by the panel is not the question or issue, nor is 120V controlling or being "seen" by the panel. The big thing here is life safety and using items that were not designed, tested, or listed for a specific purpose, which is the connection of a local fire alarm circuit to a FACP for monitoring purposes. It really makes no difference what the smoke detector's voltage is, even a 9V battery unit, the detectors themselves are built and tested to different standards. including the RF ones made specifically for these purposes. One will only annoy you when it chirps or falses, the other will generally get the big red trucks rolling.
It's not a question of can it be done, but in my case (as a pro) should it be done, combined with the liability involved, because I know of the difference between the different detectors being brought into question. You can do as you like as a DIY in your own house, but I will cite a specific example I know of in my state where an insurer refused levels of coverage based on a DIY fire alarm "solution" and how it contradicted what was signed off and issued for the C of O by the building inspector(s) after a loss occurred. Your AHJ's and insurers may be different.