Ah, well always exceptions to the rule.
Unfortunately, the music industry and probably art generally, is a cesspit of hangers on, narcissistic boosters, unreliable characters, people who'll fawn at you one moment and stab you in the back the next...and that's just those closest to you, lol.
Once you get beyond "trusted" family, friends, bandmates, management, all gloves are off.
It also doesn't help that modern showbiz is all non disclosure agreements, manicured PR, interviews only covering pre arranged Qs, ie an artifice where messaging and "insights" are superficial at best, totally fake at worst.
So, for a star like Róisín to have a moment of pure confession, a deeply held personal opinion made public, light shone upon her as a person, made known to the unwashed masses in such an abrupt and surprising way, goes on to shake people's preconceptions of her. And it was jarring for the trans ally fans of hers, all that they ever hear is Róisín the queer ally, Róisín the champion of LGBTQ+.
One of the great takes on Michael Parkinson's passing was that all his interviews were off the cuff, anything goes affairs. Interviewees had no advance warning, nothing off limits.
You couldn't imagine him today if alive quizzing Róisín about her post. It wouldn't happen. In the 70s? She'd have to expect it.
What do we have today on interviews? Over manicured, organised to the nth degree, all Qs agreed in advance with publicists, not a single interesting take elicited. Just a bunch of faceless designer suits and backless dresses with nothing to say.
So yes, in this age of blah blah blah, where noone takes a stand publically on TRA, for Róisín's unvarnished views to be outed is the shock of all shocks.