The help desk makes clear what topics are off-topic. "Other religions" is covered under Christianity.SE, Islam.SE, etc. "Hebrew Language" has its own proposal ongoing. But what about Jews, Jewish history, and Israel? Is there another site we can redirect those questions to, or should we consider building one?
It's not a bad idea, but I think that getting a StackExchange site with that particular niche off the ground would be a very heavy lift.
The Hebrew language proposal, which I think would have wider appeal, is now on its third try, having failed to attract more than about two thirds of the required commitments the last two tries.
Mi Yodeya was able to get going on Area51 thanks partly to having a pre-existing StackExchange 1.0 community to draw on. In addition, I think that Mi Yodeya has thrived (B"H) through all of the stages of its development because it caters to a constituency of people who think about Judaism all day because we base our lives on it. This level of engagement is a good fit for StackExchange's model of building communities around constituencies of professionals who spend all day dealing with a particular discipline (e.g. programming or photography). I think that there are fewer people out there who base their lives on Jewish culture to such a degree, either personally or professionally.