Proposed resolution:

This wording is relative to N5001.

1. Modify [exec.opstate.general] as indicated:

   
   template<class O>
     concept operation_state =
       derived_from<typename O::operation_state_concept, operation_state_t> &&
       is_object_v<O> &&
       requires (O& o) {
         { start(o) } noexcept;
       };