This is getting a bit hard to follow. They have announced the domestic leg is delayed? Is this happening now? Earlier it sounded like you were talking hypotheticals.
In any case, it's not uncommon for US domestic flights, to be delayed 30, 60, 90 mins.
Particularly later in the day as delays tend to accumulate by mid afternoon.
I wouldn't be comfortable with a 1h30 min layover and would look for an earlier domestic leg. What is the origin airport for the domestic sector? Are there multiple flights per day?