If you purposely pick an odd role and never say anything or give any justification as to why you're doing it, then that's potentially grounds for being reported because players can't tell if you're new, bad, or intentionally trolling.
If you explain what you're doing and why you're doing it, then it's not. So just communicate why you're doing a weird pick and you should be fine from getting in trouble.
I reject your reality and substitute my own! -Adam Savage, The Mythbusters