All 9 seasons are now confirmed as restored. Illuminate, the company behind the restoration of 24 and Star Trek: the Next Generation, spoke about the process that went into bringing all the 201 episodes to High Definition quality just in time for a pre-Revival Rewatch.

The original article says all the episodes have now been released to Netflix, but as of this publication not all of them are available in HD just yet.

You can read more about how illuminate was able to restore the series from the original camera negatives here.