I'm bored enough to check this out. Immediate thoughts:
1. If true, it's funny in a way because Joss has complained of the same type of behavior, such as when he made the Buffy movie (which I believe he walked out on as he was so mad). I can believe it's true because at virtually all levels of society is a "snitches get stitches" even if only in a metaphorical way.
Whistle blowers rarely fare well, and though you're told to fight back (whether in court, Human Resources, or school bullies), you'll be the one blamed if you do, and often they'll pretend you never spoke up in the first place when they punish you for snitching or fighting back rather than allowing yourself to be kicked (literally or metaphorically).
Even if they throw someone under the bus, it won't change anything. People rose up in this kind of environment aren't keen on changing it. They thrived, so they think others should suck it up as well (though of course they'll magnify their own hardships while minimizing the hardships of others, as is human nature).
I could cite how bad behaviors are actually encouraged in authority figures (including producers, executives, etc--and one psychiatrist who said if he couldn't study psychopaths in prison then he'd go to Wall Street) but that's a much larger issue of which this would be merely a fruit of that tree.
2. Getting tired of anonymous reports. I typically ignore them. If an article says "may" or "might" there's a 99% chance I'll automatically skip over it. And twitter mobs are even more unreliable than actual news organizations, which are bad enough as it is.
3. Why even be anonymous in cases like this? If they cite specifics, AND assuming the specifics are true, then those accused will know very well who snitched (even if there are multiple witnesses, they should have a good idea based on what was said and other factors), and since it's anonymous they can more easily get their revenge behind the scenes since in theory they don't know who snitched, but in actuality do. That is, in this case (assuming the allegations are true) it seems to me that it would protect the abusers more than the abused.
Finally, if WHAT turns out to be true? There's nothing solid yet. If he was being a jerk who threw some temper tantrums (or said other movies were crap, like I believe he said about Cruel Intentions that Sarah was less than pleased with, and presumably had other problems with him as the series progressed) then no (and if the stories of how he treated Charisma Carpenter are true then he'd have to be especially bad to outdo that). I already expect that he is, and so are most in his profession. If it's something more serious...well, that depends on what comes up. I usually skip the celebrity gossip, though.