Maybe someone can correct me, but I don't think this is absolute pitch. It is pseudo-perfect pitch, based on pitch memory, and it was already known that it can be trained.

As an amateur musician myself, I understand the desire to have perfect pitch, but it seems that the problem of perfect pitch is seldom mentioned.

Usually, people talk about the common annoyances, such as transposed music, non-standard tuning, choruses that drift in pitch, etc... but the actual hard one is that it fades away with age. First, it starts "shifting," and people will start to believe that a note is actually a semitone higher or lower than it actually is, and then eventually, it is completely lost.

There is research that indicates that this is very common, and people with perfect pitch are more likely to lose it than to keep it. This is a huge blow—imagine a whole life relying on this one skill to support all your music-related activities, and suddenly, it's completely gone.

I think this video gives a nice summary of all this from the point of view of a musician:

https://www.youtube.com/watch?v=QRaACa1Mrd4