Nowhere in the FCI does it say that once the crew member has had a chat to the FDM and a doctor (should he be able to schedule an appointment) the Absent day will be reverted.
Err... You all do understand that the four hour rule has been in the FOM for years, and has not changed as a result of this FCI.
The change has been from self certifying for 2 days as many times as you like, to two days per month. After that, see a doctor.
If the four hour thing is a "Thinly veiled threat" than it's one that has been around for years. Has anyone ever been adversley affected by it in the past?