It certainly does require you to verify coverage. However, it is a good heuristic to see if you are in the right spot.
For my area in Denver it has been quite accurate. I recently found a 5 acre homestead property with fiber next door. I ended up trenching a line myself and I have gigabit speeds!
You may even be disappointed if a carrier promises service at a location, since some ISPs have been known to renege on offers at a later date.
The only way to be sure of service availability is to order service and have somebody turn up and actually install service.
The only thing the FCC data will tell you is that service ISN’T available at a certain location.