Basically Russians have allowed access of S-300 tech to Israel that is why they have created measures to defeat it.
The zionists had some ancient s-300 system to test on. Just because this modernised model also has the words "S-300", it does not mean it is the same. Even the S-400 is ultimately just a modernised S-300, by your logic, the zionists could also defeat it?
Remember, this is probably the most modernised version of the s-300 (not including S-400) which has also been tailored for Iranian needs. This tailored part is very important to note.
Having said that all, you seriously think the zionists can threaten Iranian airspace?
They don't have the means to even reach Iranian airspace. They lack air refuelling capabilities. Even if they did, with or without S-300, their planes would get picked apart in Iranian airspace. Heck, Iranian airdefence even back in 2010 would deal with them. They are too weak to threaten Iran.
All this airdefence development you see in Iran, from Bavar-373 development, Talash air defence, Ra'ad, sadid-630 and this S-300 purchase is all aimed at protecting Iranian airspace from a potential/hypothetical US strike using their planes in the middle east and Persian gulf region. Once all these systems are operation, Iran will have easily one of the best protected, integrated air defence network in the world. No one would dare enter it unless they are willing to pay a tremendously large price in return (not even considering all the non air defence capabilities of Iran). The zionists are so weak that are probably not even factored in.
Congrats bro
Now get some batteries of. Hq-9 from china as well
Why would Iran need Hq-9 when it is now about one year away (maximum) from mass producing its own highly advanced Bavar-373? not to mention other long range system such as Talash system? No offence to our Chinese friends, but they do not have anything offer to Iran in this sector. The fighter jet sector is another issue however.