Since they effectively banned you from Chase service, what other retaliations were you worried about?
Since it's a financial institution and the accounts were closed by the bank, I wouldn't be surprised if this dinged his credit report in some serious way.
The last time I checked my credit reports, closed accounts had indications of if the accounts were closed by me, or by the issuer, and if the accounts were closed on good terms.
Having Chase cut off five accounts involuntarily probably looks pretty bad to whatever "AI" is used to create the scores.
