Single leaf yellowing?

[Orchidtinkerer]

I like confusing people so I will say leave the moss

No but seriusly a top layer of moss is generally beneficial unless one sees it is staying damp too long but I cannot see that, the roots and even the plant! look on the drier side.

So ask yourselves this, if the plant did not have one little yellow leaf - to me it looks completely healthy - would you be suggesting to change anything?

To me it looks like a root or a flower spike is pushing through the leaves and this can cause part of a leaf to die - it is a sign of good health when a plant is producing lots of new stuff even if it has to break through a leaf to do so.

I would not remove the moss as to me the plant looks perfectly healthy