I did say possibly false pretext. There seems to be evidence both from UK protests in the last 12 months and historical examples that a hard core or extreme element latch on or at least exist at the fringes of perfectly proper protest. I know you know your left wing history, so I'd point to the rise of the Red Brigades in Italy or the Baader Meinhof faction in Germany. Both were attached to legit union or student protest movements but evolved into something altogether more sinister. I'll immediately admit that in both these examples that draconian policing / enforcement had an incendiary effect. Also, I'm not having a pop at the left - the manifestation of rw 'statue protection' mobsaround the later BLM protests last summer were just as dodgy.
Overall I'd say actions have unintended consequences - both for protestors and police, and both protestors and police (or legislators) have a responsibility to take extreme care exercising their powers. At present we are seeing some examples clumsy policing, some protestors abusing their rights to protest, and opportunistic legislation.
They might have for all I know (I've not looked) but did Italy or Germany respond to terrorism with restrictions on peaceful protest like in this bill?