Considering many people only arrive at the airport 2 hours before departure… 2.5 hours is actually quite generous. It doesn’t take 30 mins to get from international to domestic.
The concern would be the on time arrival of the connecting flight. But your bags will be checked through, and presumably you’ll have boarding passes too. So if your inbound arrived at 0930, even as late as 0945, you’d still have time to get across to international by 1015, and be through well in time for boarding.
But yes, if the inbound is delayed such that you can make the onwards flight, VA/SQ will rebook you for the next available flight.