As far as FRMS goes it seems like most of the prescriptive limits of yesteryear have been removed from the rules and individual companies are now required to demonstrate that they have a policy on how a pilot should report fatigue and that they have a 'just culture' that encourages pilots to report fatigue. They can then negotiate duty limits ( in exchange for higher salaries) that are in excess of what the old prescriptive limits used to be.
The policies make it clear that it is the pilots responsibility to call fatigued.
The responsibility used to be on the operator to ensure pilots were not rostered to exceed specific limits, those limits are now higher and the responsibility is on the pilot to report.
It is a bit like the Transport Department telling all trucking companies that they can negotiate their own speed limits with drivers so long as they write a policy on how truck drivers are to report when they get the speed wobbles.