Are these different neutralization pathways?
Both fast reactions happen in parallel, acting as "first comes, first served". 

Concentration of water molecules ( $\pu{55 mol/L}$ in water) is much higher than $\ce{[H3O+]}$  for diluted acids, so oxide anions meet water molecules much more frequently.

If the oxide anion meets water molecule, it will not wait for hydronium. 
Additionally, hydronium ions would be rather depleted by reaction with hydroxide ions next to the oxide surface. 

Be aware that $\ce{Na+}$ ions are just bystander/spectator ions, so it is more illustrative to write equations as ionic equations:

The main reaction:
$$\ce{O^2− + H2O -&gt; 2 OH−}\tag{1}$$ 

The secondary alternative reaction:
$$\ce{O^2− + H3O+ -&gt; OH− + H2O}\tag{2}$$ 

The final reaction:
$$\ce{H3O+ + OH− -&gt; 2 H2O}\tag{3}$$