question on dubious emails about email accounts being upgraded
It looks phishy: bad grammar, ambiguous, threatening. In an era of spoofing, phishing, social engineering, spamming, scamming, lying and efforts to avoid becoming prey to said maliciousness...I would just delete it. Even if this email were legitimate, I would still delete it due to the moronic employee having haphazardly crafted it.
Your gut instinct is your natural protection. Even with the slightest hesitation, I'd delete it. If Cox was to terminate your service & account because you haven't "updated" your account, Cox will send you a letter. Cox wouldn't lose your business due to an account setting.