you need to insure.. that there is moisture thru out the entire root mass that you planted ... drip irrigation does not provide moisture to depth.. unless it remains on for many, many hours ... i would take a hand trowel.. and dig slightly away from where you planted the root mass.. and dig down about 6 inches.. and find out if there is moisture at depth ... and the soil should simply be damp.. not sodden ... they need to remain moist for about 2 years.. to grow the roots to recover from the planting.. how that all works in your soil .. in your garden.. is a mystery to us ... you have to figure it out ... do not let them freeze into an ice cube for winter.. so soil drainage.. and where you actually are in NY .. is important .. i do a lot of drip irrigation.. but i have never used it on trees .... it OK to maintain soil moisture.. but might not be enough to insure it.. 6 to 12 inches down in the soil ... after your discovery of what is happening a few inches down.. you may need to pull out a hose.. and let it trickle on each plant for an extended time... ken

They froze last year or they are not getting enough water now. Either way, they are dead or nearly so when they look as you have described.

They look in reasonably decent shape to me. You will often get some browning and/or loss of foliage at the base, primarily due to the topgrowth shading it out. Wall is probably not helping much either. As long as there is not a steady progression upwards, they should be fine. Winter burn - typically wind desiccation - is unlikely to be much of a factor in October, when this was posted. And I will refrain from commenting on the reliability of horticultural info presented by The Spruce or any of its garden writers except to say that there are much better sources.

Yes, around here we call that deer pruning. It's a shame- must have been lean pickings for food this winter near you. They're not going to regrow that foliage- if you want to keep them your only hope is to expand that bed to make it deep enough for some flowering shrubs to hide the devastation. And unless you use broadleaved evergreens or another conifer it will be bald and unsightly all during the winters. I'm afraid I would be compelled to pull them out and start over. And 20 year olds will be quite the chore to remove unless a chop at ground level works for you. If you do start over I'd suggest choosing four or five different types of plants (trees conifers, shrubs) and make a mixed border alternating between them all. That way if you lose one or one gets deer munched it is easy to replace without having to match species or size. This almost always works out better in the long run.