Normally companies don't publish details of internal employee doings and especially not complaints. That's just not done. What if they're mistaken about the contents of the article? I'd be furious if a company put details of some internal complaint I made on their blog, if I hadn't actually gone and tried to get it into the press.
Criticism is not abuse. They’re also not doing the best job defending themselves since they offer no concrete proof, testimony, or narrative. Who were these employees? What happened? We don’t know, but are left with some empty promise of a statement that Coinbase “handled it internally.”