It does, it's a rare exception, but they were neither known back then nor have been exploited yet.

Interestingly, Israel was brokering a deal between Egypt, the PA and Hamas for exploitation of this field. It would have resulted in energy independence for Gaza and a significant income stream for both Hamas and PA (or more realistically, the offshore accounts of the leaders of both governments). As far as I know, it was close to being finalized, with ongoing negotiations until October 7.

It'll never happen now, of course.