That is discussed in the video as well. It would be an elaborate fake - map is very detailed
If the IDF found such a map, why would they publicize it? Wouldn’t the info be more valuable if Hamas did not know the Israelis had it? Makes me think that this is disinformation the purpose of which is to freak Hamas out.
Leaving stuff to be ‘found’ is a very old tactic. The British command used the Haversack Ruse, to fool the Turks defending Beersheba that Gaza was going to be the goal of the observed military manoeuvring.