Yep, that's an example of two players who were labeled as 3rd liners and essentially rose above those standards to become 1st/2nd line forwards. It happens, which is why I don't like to label "ceilings" on players. When I say I believe Gaunce has 3rd line upside, what I mean is I believe he will become a good 3rd line center. Could he become a 1st line center? Yup, it's just too damn hard to predict how certain players will develop, so it isn't wise to rule anything out. It's not like I'd be shocked to see Gaunce as our future #2C, but I think he'll top out as a good #3C. I sure hope I am understating him, and I hope his development curve peaks late.
Also depends on the team. Bolland was the Hawks' 3rd line centre, he'll most likely be moving up in Toronto.
It's not like being the third line centre because Henrik and Kesler are ahead of him means he's a bum. (Are you listening Mr Hodgson???)