The truth about Brontë Films and TV
The sister company of Brontë is Snowed-in:
J. K. Rowling DOES NOT hold any positions in either of the companies. The one who does is Neil Blair:
So Pottermore, the Harry Potter Films, Fantastic Beasts, The Cursed Child... they are all completely UNRELATED to Brönte. Covid affected the sales of The Cursed Child (which had to temporarily close) and Fantastic Beasts (which had to delay filming, costing millions of dollars). But neither of them plummeted their sales because of any boycott, it was because of Covid, and did not affect, in any way, to Brönte.
J. K. Rowling also has, as I said, no official position for either production company. She is good friends with Neil Blair, who's her agent, and obviously they work together in plenty of things, he's very supportive of her, and I'm sure they conceived the idea of Brönte together, but she does not really work there.
So why is the press saying that Brönte's profits plummeted?
Long story short: Covid. It is unrelated to any boycott or scandals or anything. What happened was that Brönte, as you saw, is a very small production company. They do Strike and The Casual Vacancy, period, and they do so with the BBC. Troubled Blood should've been filmed a year before it actually got filmed, but it suffered because of Covid mainly, as filming here in Britain was halted, and also because conflicts of schedule with Tom Burke and Holliday Grainger, and because Holliday was pregnant during Covid, and her twins are about to turn 2 years now, if memory serves me right. So basically there were a number of factors that meant they couldn't film when they ideally would've wanted to, that things had to be delayed and halted, and then filming has gotten way more expensive, between other reasons because now you have to pay all the PPE and Covid testing for actors. So of course their finances have taken a blow.
But no one boycotted them. Besides, no one COULD HAVE boycotted them. The series go to BBC (which is state-owned and paid for by the taxpayer) and HBO (private through subscription), so they've got their money pretty much guaranteed.