Losing 2 leaves on newly mounted Phal.

[TheCanfield]

I mounted a NoID Phal Keiki (3 years old) aprox 2 weeks ago to a piece of Mopani I purchased at a local PetCo (Mopani).
I soaked the wood, changing the water twice daily, until the water was a very very light color. I now water the mount by placing the whole mount into a bucket of water (not shared by any other plants) for roughly 15 - 20 min every morning.
It has a root that has continued to grown w/o any issues and a new root has started to poke its head out. The only concern I have is that the two oldest leaves have started to shrivel and turn yellow.
Should I be concerned in any way or is this just a shock symptom?