Apparently you can still check the power-on hours of the individual heads in FARM even if the global hours have been reset to match a reset to 0 value in SMART. For now at least.
All of this data is just written to the service tracks (Host Protected Area) which tools like hdd.by/victoria have long been able to read and write to, so this news is about the encryption of those FARM logs being broken.
Most people are simply going to go by SMART numbers anyway without bothering to see if the numbers match those in FARM, which besides not being encrypted, is even erased/reset just by flashing a factory firmware to the disk. Which may be why HDD makers don't just post those up for download, so you have to get them emailed to you by support. I recently flashed a 100,000 hour VelociRaptor and found SMART reset to 0 hours, so returned to brand new status.
This is why recertified drives usually have less than 24 hours on them (in SMART, they don't reset the FARM)--because the "refurbishment" is simply flashing the latest firmware then doing a zero-fill and surface scan