In this paper, the assessment of existing theoretical models for the vibrational state-resolved Zeldovich exchange reaction is carried out on the basis of comparison with the results of several quasi-classical trajectory (QCT) calculations. An error in the theoretical model proposed by Aliat is corrected; after correction this model provides a very good agreement with the QCT reaction rate coefficients. Then the model is further generalized in order to take into account the vibrational state of the reaction product, namely, of the NO molecule which is formed as a result of the Zeldovich reaction. The generalized rate coefficients are in fairly good agreement with the QCT results in the whole range of temperatures and vibrational states of both reagents and products. Using the non-equilibrium Boltzmann distribution we study the multi-temperature reaction rate coefficients, obtained by averaging the state-specific ones. The effect of the vibrational temperature of the reaction product is evaluated. It is shown that variation of the NO vibrational temperature does not affect significantly the rate coefficients. Thus both commonly used assumptions that NO molecules are produced either in thermal equilibrium or in the ground state are valid for simulations of non-equilibrium high-temperature flows.