If we're just talking about mixing into an EQ, there's nothing inherently wrong with that. I used to mix into a pair of Pultecs (and later, the UAD Pultec emulation) all the time.
That said -- IMO/E, you should "know" and have that EQ inline more or less when you start. You're (hopefully) not using it as wholesale correction, but as a "flavor enhancement" that otherwise wouldn't be there. If you're throwing EQ's on late in the game because "the whole mix has too much low end" then go back and find out why.
IMO/E, YMMV, etc., etc., yada, yada.