So I'm kinda split on this.
On the one hand, if we take her word for it in terms of the fact that they made her an offer and she said "no that's too low" (completely ignoring actual amounts for now) and turned them down, then Platinum lied when they previously said Hellena Taylor wouldn't be reprising her VA role due to "scheduling issues".
On the other hand, unless we know: (1) what she got paid before for her other Bayonetta work and (2) what amount she would have actually settled for, it's hard to make a judgement call either way.
Obviously companies will use vague reasons like "scheduling issues" to diplomatically say "this person will not be coming back... meet the new person" but if it's a lie then it's a lie. Wouldn't make it excusable just because everyone else does it.
Full disclosure: I give zero shits about the Bayonetta series (never played it, have no interest in doing so) so I like to think I could take a relatively neutral line on this.
Also I just listened to a comparison video of Taylor and the new voice (Hale) and yeah I agree that her voice is way better than Hale's. That said, I'm pretty sure there are loads of British female voice actors who can do that stereotypical "sassy, almost villain-like, posh" voice. Their choice to go with Hale is a bit bizarre from what I've listened to, especially if they are paying her more (in which case why get rid of Taylor in the first place? is there more to the story than just money?).
Hell, even I know a few super posh older British women who would be glad to do that work for 4 grand.
Overall, surely VAs know that they (for obvious reasons) are inherently more disposable than physical actors. That's precisely why you see actors often successfully negotiate big pay bumps for sequels when the initial movie is successful (assuming they hadn't already signed up for multiple movies).