Why wasn't there a big cut?
Most large PDGA A-tier and larger events have a sufficient cut so that the last card is teeing off at 2pm or so at latest.
In this manner, the competitors can be done and awards ceremony wrapped up and folks on their way home by dinner time.
It also gives some flexibility if there is a weather or other unforeseen delay.
This and other events with similar timeframes are running a very thin line between completion, and total disaster. Any emergency which comes up and delays the tournament by even an hour is going to result in competitors not able to finish by dark, and the entire Sunday round thrown out. There is no Monday completion of a tournament in disc golf.
This is the way it has been done for decades.
Why are folks changing things now?
Good luck traipsing on this razor thin wire.