Headers running lean???

I got JDL catless headers with an OFT for my ‘13 BRZ. I have a friend who told me to be careful when I put them on as my engine might run lean and spin a rod down the road if it’s not “tuned properly” (I’d just be putting the stage 2+ oft tune on it, I also have a JBA catback, stock front, and perrin overpipe but no intake mods)

I smell bullshit, but what are your thoughts? I’ve heard good things abt OFT for NA builds.