What would be the benefit in catching young adult drones, separating them from the rest of the hive, and sublimating oxalic acid on them? If you simply sublimate oxalic acid into the whole hive* at that time you would kill all of those parasitic mites**, plus those on female bees and any others caught out of capped cells, so at least as effective, probably more so. Much easier, less disruptive, and more effective.
At that time in the season it is the inability to affect mites within capped cells that is the main limiting factor on treatment with oxalic acid, which such an approach would not help with.
If the findings prove to be accurate, I can see the impact on measures such as sampling for sugar roll/alcohol wash testing; however treatment of parasitic mites is not particularly the challenging part of varroa management and would not be improved by treating only those feeding on young adult drones.
* Strictly speaking, hive without honey supers, though with 0 day withdrawal period you can put supers back on the hive after treatment, and oxalic acid sublimation is not a prolonged release treatment. Queen excluders, where used, would already prevent drones being in the removed supers in this case.
** They have been shown not to be in any way phoretic, so I avoid using the term, but I mean parasitizing adult bees in this sense i.e. those not breeding in cells with pupae.