How do you see it, is it already electronic music or does it count as acoustic? As I understand it, it is recorded on handpans. But then the sound is changed a lot and sounds like drone, ambient etc. to me. So what counts more, the final sound or the way the basic sound is produced?

Reminds me of discussions at the time when instruments like the clavinet emerged. There, for example, metal reeds are plucked, then fed to the electronics via a pickup (usually a simple coil around the reed) and then processed as desired. Basically, the same way it is done with any electric guitar. But despite the distortion and modulation effects, it is not automatically described as electronic music. Or should we be more flexible with the categories?

^ Well, yes, but that doesn't answer the OP question. And especially when one considers that electronic music existed well before the invention of the synthesizer, the question only becomes more pertinent. For example, musique concrète - considered being "electronic music" - used recorded sounds that were then processed either through tape manipulation or electronic manipulation. In that sense, the recorded and then processed handpans can thus be considered electronic music.

Listening to parts of the yt-vid put up I would intuitively label this ambient electronic. That said, the music is of course more important than the label we could stick on it...

No, you are confusing amplification with a microphone and PA with electronic music. All acoustic albums and symphonies use microphones to record. In a concert setting microphones are used to amplify the sound of voice or acoustic instruments. They are still acoustic sets in that the instruments are not solely reliant on electricity to make them work. There is a distinct difference between a piano and synclavier, moog or hammond organ, in that electicity is the sole means by which music can be made with the latter three, as opposed to a piano which can be played sans electrique.