"not too long ago those particular views were in fact something that was doing quite a bit of harm to trans people"
I understand what you are saying, but there's a pretty big concern right there in the conflation of 'intellectual position' vs. 'ammunition supporting specific movements'.
That some systems take another persons nuanced views, possibly out of context, and use them to promote their agenda, should not in any way stop people from being able to have public discourse about them.
The fact of the matter is, JK's views are not anti-trans, even if they could be used by others as such.
However much we can decry other parties for using her words in a manner in which we do not agree, the same thing applies in the other direction: we don't get to shut her down because she doesn't 'toe the line' on the current, 'new' orthodoxy.
JK's views are reasonable.
It doesn't matter that 'some other organisation using those words to do this or that'. It's relavent, but not to the extent of censoring her.
Now - if we're talking about crude, casual bigotry from 'powerful voices' and the public effects of that, i.e. a 'Famous Person' tweeting 'bad things' - then yes, this is just populism.
But anyone willing to make a serious point within the boundaries of civility needs to be able to make it, full stop.
People can debate with JK, they can even ask her to not make her statements public 'because bad people will use it as ammunition' - but there's no way her words cross the thresholds of uncivil, and she should be able to make them without fear of being banned.