Ambonosa - beginning of an end?

Phalaenopsis Ambonosa looked just fine, grew a new leaf and two new roots since I got it totally rootless. Started second new leaf.
Suddenly in one day three old leaves got yellow and dropped:



Probably because those two small roots cannot handle that many leaves, but why would it start new leaves then?



Maybe it is just a start of its death. I re-potted it into smallest net pot, but even the newest leaf start has some black patch, so overall it doesn't look good at all...