The lawsuit in the first article is about CS's decision and authority to invoke the write down (Section 7), not about a violation of the capital stack.
The AT1 contract specifically states "The Write-down may occur even if existing preference shares, participation certificates and ordinary shares of CSG remain outstanding."
The first article agrees, saying "They also contained a clause enabling them to be written down to zero by Swiss authorities should the bank no longer be viable, regardless of whether stock holders were also wiped out."
Again: the capital stack was respected, not violated.
Your second and third links are only about CS making false and/or misleading statements in its public filings. I don't see any specific mention of AT1 bonds in those two links at all. In fact, the first of the two articles is about a shareholder lawsuit, and the second specifically says its for those who hold stock or options.