To me direct sticking to the concrete would be the only way to go, same as when we do for parquetry, cork, vinyl, ceramics etc.
We don't adhere anything to concrete without grinding the slab 1st. You should do a moisture test as thats the minimum for Australian Standards.
No more than 1mm over 150mm or 6mm over 3m.
Moisture Fix or Densi proof the slab, flood coat with K15 or similar then a quick hit with the Polyvac with Supa Sander head the next day & off you go direct sticking to your hearts content.
I can't understand why anyone would stick plywood over a timber floor, it just seems unprofessional to me.