Tampa keeps Eastern Time, nine and a half hours behind India in summer and ten and a half in winter. When a storm closes offices on Florida's west coast, the Indian evening shift is the part of a client's support that keeps running. That is the case for WhatsApp here: staff who cannot reach a building can still reach a phone, and the team that answers is awake.
It only works with consent collected in calm weather. A client's employees should opt in to your support number as part of normal onboarding, with the second number they would use if they evacuate. Asking for that during a hurricane watch is too late.
There is no promotional thread to plan. Meta says WhatsApp does not currently deliver marketing templates to people with US phone numbers, so a Tampa programme is made of the notices, codes and replies a client has asked for. For a firm whose reputation rides on how it behaves in a storm, that is the right shape anyway.