Load of Rubbish.
What a load of old twaddle.
Daesh does not actually mean what you say it does i.e. "the name of the medieval terror bastards". Daesh is a word in its own right and it is a pejorative Arabic word that means a group that impose their ways and will on other people. When the West was calling ISIS ISIS, the Arabs were using a bit of word play and calling them Daesh. Slowly but surely the West caught on and they are all calling them Daesh nowadays.
Soooo, do not forget that it is a word (not an acronym) in its own right and could easily be applied about Fanbois, Christians and yes even Saudi's.