That was true last season; it is a lot less true this pre-season. Derrick has indeed been taking stand up OLB snaps in pre-season, whereas he did not last year.
This is true. But I think Andy's argument is - which I'm completely in agreement with - is that this is exactly what the preseason is for: trying new things that you wouldn't ordinarily do during the regular season. I personally don't want to see Derrick Burgess starting at OLB during the regular season.