One of the characteristics of the Mexican revolution from the Spanish is to replace the construction of the Tavern with the Saloon, but doing so also eliminates the possibility of building the Native Embassy. This is due to a bug in the code.
In the tech “DERevolutionMexico” it is written:
<effect type="CommandRemove" tech="deTavern">
<target type="ProtoUnit">AbstractVillager</target>
</effect>
And it should say:
<effect type="CommandRemove" proto="deTavern">
<target type="ProtoUnit">AbstractVillager</target>
</effect>
This is why both the Tavern and the Saloon appear on the Settlers command card, occupying the space that the Native Embassy should have.