Eddie went from the most exciting fighter to someone who ekes out victories. I think the UFC has some control on who people are calling out.
Silva started doing to to GSP years ago, even offering to go to 170 if that's what it took. I suspect Dana told him to stop because GSP didn't want that fight.
From the UFC's point of view, calling people out is to hype up potential matchups and right now Eddie's stock is low.
And about the Frankie title comment, after the $500g payday that Mendes got, I think a lot of guys want Mcgregor just to be associated with a big event that comes with a big pay day.