However, more and more, I see / hear (alledged) producers and engineers talking about "Mastering for a genre". For example, getting a "pumping master" for an EDM track. In my mind, the pumping feel would come from all the side-chaining and automations in the Mixing stage. By the time the song gets to the mastering stage, it should already have all that side-chaining / track specific limiting / compression / etc. The Mastering stage is just optimizing it for mass production.
One of the plugins I'm learning to use, Izotope 8, has "Genre-Specific Mastering" presets, These presets are very cool and will often noticably color the texture of the song. But again, to me that feels like something that would be part of the Mixing domain.
So either my understanding of Mastering is naive, rudimentary, and outdated or the lines between Mixing and Mastering are getting blurred. Before all these tools were available to plebeians like myself, I believe you had to send your music to a Mastering house and they would send you the final output. So I imagine you probably had minimal input on how you wanted the master to sound because it was just sent out to get optimized and not "texttured" or "colored".
I'll refrain from calling myself a "Mastering Engineer".

Cheers