The media - not just traditional print media - is feeling increasingly fragile since the shift away from newspapers.
So while there's an appetite for it, news sites will cover any topic that needs covering. So, for example, the existence of Bolsonaro would have mostly gone under the radar had the septic spraytan not endorsed him, at which point the media felt it could start calling out the BS that was coming from there.
But it isn't just the slimy swampcleaner salesman, when antisemitism scandals that mention Israel erupt, that becomes an acceptable time to talk about their bad behaviour, under the guise of "these are the legitimate criticisms that this person is / could be raising". Do Israel stop being human rights abusers when antisemitism is not in the news? Of course not. But it isn't seen as newsworthy enough unless something local has piqued our interest.
When people are killed in racist attacks by american cops, BLM activism and systemic racism become part of the news cycle again. Does racism stop whenever there hasn't been a high-profile racist murder recently? Of course not. But without that hook, people looking to follow the story won't be clicking on every link.
And unlike traditional newspaper, where you could buy the thing just for the crossword and the advertisers will still pay, only the individual stories and individual page loads bring revenue. And so the media can no longer afford to finance investigative journalism that might not resonate with the public.
So I don't think it's that the rhetoric that has changed. News cycles are responding to what they think our attention span is, based on the numbers they see in the ad revenue. And in this specific instance, while China has had an uneasy relationships with the Uighurs since at least the 1950s, it's the secret and courtless detention and "reeducation" centres that have really got people riled up (shhh... don't mention Guantanamo) and that's only been happening since around 2017.