Answer: This is truly unfortunate. Also, it is very difficult to develop an opinion long distance, so here are some considerations to keep in mind while you try to evaluate the trees.
Standard planting practice is to remove all wrappings, burlap, twine, containers, anything that could become binding on the plant as it grows, at planting time.
Occasionally labels are left on temporarily for informational purposes but these should then be removed by the ongoing caregiver before they could bind. Similarly, any staking materials would also need to be removed before they could constrict growth and should never be tight enough to cause damage to the bark as the damage may only become evident many years later.
The roots should also be directed outward from the root ball at planting time to encourage them to grow beyond the planting hole and into the surrounding native soil. If the roots fail to do this, you might see browning later on due to the roots growing in a constricting circular pattern underground.
There are also numerous possible pests and diseases as well as different apsects of the cultural conditions (too wet, too dry, heavy clay soil, etc. ) that could cause the same symptoms.
Having said that, I am not clear on the connection between a fungal infection and constricted circulation within the tree; in my experience these would be two distinct problems.
I think you might want to get a second opinion as to the cause of the browning since these trees are subject to a number of pest and disease problems that could cause browning. A professionally trained and certified, well informed arborist who is familiar with ornamental trees should be better able to advise you as to the long term prognosis of the trees based on the on-site inspection.
Also, your county extension may be able to help with the specific diagnosis of the problem(s) and also have suggestions as to what you might want to do next.
I'm really sorry about the trees.
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