hard to see from photo observation like Maura stated any new roots even with photo editor & zoom, justs makes it worse with pixel distortion.
are you seeing white thinnish roots (wire type thickness) with lovely lush apple green tips? Great if you are!!!!!!!one more step up the ladder.
On confirming new root development i strongly advise now to keep plant in situ, secure and stable as it has the environmental changes to fight with aswell - no moving. Changes will occur from 1 sq meter to the next so dont want to exhaust it.
While not close enough to 100% definite survival yet, those root tips will be extremely sensitive and vulnerable esp to toxicity. Any contact with salts etc will affect very quickly even aerosols/ gas from curing acids in silicone used for window seal for eg, but your s/h is a good move for a humid ambience which would serve very well. Avoid any chemicals, organics,ferts, pests fungus treatment. It will be using the 1 chance it has left and root dieback is certainly a major threat. Same game that is played by many orchidists in root loss incidents and heat/ sun avoided due to evap/ transpiration, humidity as an aid to help progress and its remaining storage and reserves of nutrients which will be minimal with psb situation. Leave in s/h situation undisturbed. Those new root tips can burn and dieback simply coming into contact with anything even slightly hostile smething that a mature orchid would cope with.
Fingers still crossed!!!!Nutrition values wise is a 'damned if you do damned if you dont' situation at mo. Perhaps fert extremely weak diluted even foliage spray, any little thing helps. To strong and to frequent may pose burn issue. Difficiult one! Lacking in calcium potassium magnesium or deficiency off has symptoms of 'necrotic' dead tip root dieback. Plant will abort and struggle goes on longer.