That is the trouble with laws like this and ones criminalising say offences against religious feeling. They always too open ended and are always abused in all sorts of ways.
As for what is, or is not fake news, etc you get in to a discussion about quantifiable and verifiable facts and reality vs subjective opinions about it, or as said thing are directed by someone’s agenda. However, there is also shit that is outright false… Like 98% of everything trump says, what you see on infowars, those “bill gates 5g microchip rona” bullshit that is prevalent on facebook. Should crap like that be criminalised?
No, definitely not… But we do need to figure out some tools by which we can get help to the mentally unstable individuals who believe and feel compelled to act on that crap. Thereafter we also need to figure out what to do about extremists and fundamentalists with similar inclinations, and the will and means to take advantage of the other group.
Laws like this are not the answer though. Too easy to abuse.