Dumb comparison. SQ is legally allowed to fly into TLV. The 3 you mentioned are NOT. The issue of SQ flying a fifth freedom TLV to NYC, is that whatever is left of Israels flagship national carrier will crumble..... Maybe if they're as persuasive as Air India...
Maybe Singapore law doesn't bar them from flying into TLV, but I've spoken to someone who lives in Singapore, and he told me that the reason it's not likely to happen is that they wouldn't do something like this without the approval of the Malaysians.
OTOH, even if SQ were to fly to TLV, the likelihood of them doing a 5th Freedom to NYC is less than zero. The opportunity is for flights to Asia-Pacific and Australia, no reason for them to enter the highly competitive market with established players of TLV-NYC (especially when they already have a 5th Freedom FRA-JFK).