Yes, wrapping the arborvitae loosely will decrease direct sun and slow the winter winds which will lessen any winter desiccation of the needles. Any newly planted needle evergreens or those always exposed in windy locations will benefit. There will always be some annual needle browning in the interior of the evergreen as new growth pushes outward, the inner most needles will be the ones that naturally brown. Be sure to water them well just before you put the hose away for the season.