Now one could reasonably argue that it wasn’t due to the firing. However, the burden of proof lies with the people claiming that the concurrent loss of revenue and profit had nothing to do with the firings.
And Twitter being a private company it’s unlikely anyone can ever get the data to support that claim. Further, Twitter’s unique nature as a vanity project for the owner makes even public statements bh thst owner highly suspect, since they have a vested interest in making this look like the right decision and disclosure laws don’t apply to private companies so he can basically lie and still be ok.