Yes it can raise fares - and that's not some unexpected downside it's just pricing being more transparent.
If airlines have a cost to being late/cancelling, then that will balance against the cost of having e.g. N% slack in staff/aircraft/schedules. It most definitely helps reduce cancellation and delays.
If you are curious whether this is bullshit, the best experiment would be to time travel back a N years, take two similarly sized continents with lots of flying, and use this type of regulation on one continent and not the other.
If airlines have a cost to being late/cancelling, then that will balance against the cost of having e.g. N% slack in staff/aircraft/schedules. It most definitely helps reduce cancellation and delays.
If you are curious whether this is bullshit, the best experiment would be to time travel back a N years, take two similarly sized continents with lots of flying, and use this type of regulation on one continent and not the other.