I have seen people on Twitter get angry over less information. What’s wrong with escalating this internally? We can both agree that there should be a real investigation right?
The original author has the option of reporting this pretty directly to Tim Cook (or, presumably, a team of minions acting as his mail filter), naming names, projects, etc. He'd be well advised to take this report seriously.
Alternatively, the author also has a number of further options. They could go to the press, as mentioned in the article. They could also find themselves a lawyer. IANAL, but the allegations, if true, would seem to constitute a constructive dismissal[0], which (apart from human decency) is a reason why Apple should have every interest to investigate the allegations.
Any of these three options would seem to me to be a promising way to get this investigated.