Personally, I believe there is about zero percent chance of Armenia sending any weapons to UA, especially missiles and AD. They also do have lots to lose: Armenia’s imports from Russia are worth nearly $2B and exports $1B, while the GDP of the country is about $14B. So there is quite a bit to lose.
They’d also might need those assets themselves because you never know what the future holds, especially if you start supplying Russia’s “enemy” with missiles and equipment that you bought from Russia (or inherited) and you are that small of a country that most don’t even know exists. Especially, with the current situation they are facing with AZ. It just makes zero sense and I do not find it believable one bit. But that’s just my opinion.
Also, as per a few sources, Armenian MoD said the reports were not true. They are also claiming it is AZ that is responsible for spread of false info. This is TASS - I cannot find anything that could be called reliable.
Yerevan debunks reports of Tochka-U missile system use in Nagorno-Karabakh
Edit: Have been thinking about it now for a few minutes. What would they be gaining by such an act vs the risk they’d be assuming? There is nothing I personally can think of that would make such a move anywhere near to being logical, but outright dumb. So yeah, I do not think there is even a slightest chance this can happen. But we shall see, I guess.