It's relatively common for publications to lazily only reference an action that resulted in a legal outcome, rather than the justification provided for the outcome.
For instance, Bob imprisoned for car bomb rather than Bob imprisoned after judgement rules deaths unlawfully resulted from Bob's malicious car bombing.
Had Bob's car bomb been on a film set and no one hurt, Bob would hopefully be fine.
If you read coverage with this in mind, then what matters is more a case of how likely an action is to be unlawful and thus how lazy the publication is being.
If someone blows up a car, we'd assume it was unlawful. If a company stores passwords unlawfully we'd assume it was unlawful and hopefully for good reason...
From GDPR: "personal data breach’ means a breach of security leading to the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to, personal data transmitted, stored or otherwise processed"
A typical security policy for securing passwords is to never store them in plaintext.
It would be a rare situation for the storage to not be accessible (what would be the point of storing it).
Thus it would seem fair to assume that in most cases plain text storage of passwords would be a breach of security (internal controls breach) would implicitly also be a breach of personal data (legal definition) as it would at the very least be accidentally accessible to staff, contractors or third parties (whoever hosts the storage).
So, it will likely fit the definition of a breach.
But, it still needs to escalate to a point where it would be recognised as serious enough to warrant action (like reporting to data subjects or regulators).
There are situations where storing passwords in plaintext may not warrant reporting or fines, such as if upon realising the breach it was evident that nobody had accessed the data and it was destructed before harm could be realised; but I doubt anyone would ever know about these situations happening in companies so it's fair to assume they wouldn't reach major news sites.