Pedantic question about 'otro'
I can rephrase the sentence to avoid the problem; I don't want to because I'm trying to do understand the effect of implied gender on inclusion in a category.
If I'm talking about the artists María and Roberto, I could say
I will meet Roberto and the other artist (María) on the corner.
Encontraré a Roberto y a la otra artista en la esquina. (because they're both artists)
Encontraré a Roberto y a la artista en la esquina. (because Roberto is not a female artist)
Which is correct?
Regardless of how you say it, Otra refers to Maria - gender agreement.
You also have changed the meaning of the sentence slightly. (ignoring your introductory explanation)
If you say ..."the other artist"... we know that they are both artists.
If you say ...Robert and the [female] artist...then we only know that one of them is an artist.