Maybe I'm missing something, was the PM3 discontinued long before Oppo announced they were stopping all of their audio line? I had assumed that they stopped selling the PM3 first as they would run out of stock first as it was clearly the more popular (affordable quality so no surprise) so there would be stock of the PM1 and 2 for longer. Now I'm taking an educated guess here, but I suspect that Oppo knew long before the official announcement that they were ceasing production of the audio line so the PM3 went out of stock first would be my guess. Again, I could be completely wrong. Just ask my girlfriend, she'll tell you that I frequently am wrong.
Oppo was still offering the PM-3 (black only) when they made the announcement, though they had not any PM-1s or PM-2s for some time before that.