Call Delta reservations. What time does your flight arrive in to ATL?
It appears that minimum connecting time is 35 minutes D to D (domestic to domestic) If D-I and STT is Considered as international in ATL, it will exceed legal connecting time. (Obviously STT is not Intl, as passport is not required for USA originating passenger, but it may be considered so for connecting pax).

Therefore, per your original message, you do not qualify as scheduled connection - invalid connection. Therefore it is Delta's responsibility to book you on a valid connecting flight without penalty, change fees etc, or give you a full refund.

Problem is, this will change several times as DL adjusts their schedules seasonally, and conditions change in the hurricane impacted islands. Six months out....all bets are off..