I wonder if woke types keep on pandering to this stuff whether it will become a bit "boy who cried wolf" in years to come - I mean it provokes quite the overreaction at the moment but in the long run will playing the race card over routine incidents mean that actual racism accusations are then diminished too? [..]
Maybe, but I think not and certainly not before it gets far worse. The fashionable authoritarian bigots already have far too much power and they're very skilled at abusing it. I think a more likely scenario is that they will succeed in their goal of creating an authoritarian regime based on their preferred irrational prejudices. They're already at the stage at which they can freely blame their victims with false accusations and face no consequences even if their accusations are proven false, while their victims continue to be presumed guilty and suffer forever for it. That sort of thing doesn't go away easily, let alone reverse. We're nowhere near the peak of it yet. Politically skilled people driven by irrational prejudices can cause a lot of harm when they have power and are unchallengeable. It will get far worse before it gets better. If it does get better. With the vast amount of surveillance made possible by modern technology, there's the possibility of an authoritarian regime remaining in power indefinitely.
I think that sooner or later they'll have to search for a different target group, but they've already laid the groundwork for delaying that as much as possible by making up a target ideology and attaching that to their target biological group identities. So even if they succeeded in enacting the final solution to the white male problem they will still be able to maintain power by blaming white men for a while afterwards. Anyone not wholly obedient can be condemned as being contaminated with white heteropatriarchalism and silenced. Eventually they'll have to go down the racial purity road and start targetting people who aren't "black enough", but that might take a century or more. It's inherent in their ideology, of course. All racist ideologies contain the idea of racial purity. They're already laying the groundwork for targetting people who aren't "black enough" and they are, of course, blaming their victims as usual. The label they're using for that is "colourism".
Maybe it'll swing the other way eventually, but before that we're going to have a society even more racist than early 20th century USA was. Same thing, different race. But even worse. Because that's what these people want.