Cedar Blight or Simply Stress?

Hi, I would like to have some professional advices on my cedar's situation. I have planted some cedars (Emerald) for a couple months, and recently the bottom parts start becoming yellowish and some tips even become black and drop off. I have consulted different people and got different replies: some said it was just transplanting stress, and will recover after the roots have established; some suspected I had overwatered the trees and it is blight infection as the bottom parts are too moist... I'm confused and therefore need some sharp eyes to confirm the case.

Basically, I have carefully monitored the moisture level in the soil throughout the summer with mositure meter and my good sense (finger). Also, I use soaker hose to water them every second day, soaking for a good one hour or two after work. The soil is considered sandy clay. I have mulch covering the base to avoid moisture loss. So, I will say everything I can do to keep the cedar hydrated, as people told me cedar need water in the first season after transplanting.

Attached some pics, any advices are welcomed!

 

I would go with the planting stress.