I think it's one thing to look at unproven guys like Diaw, Barbosa, Jones and Bell and not expect anything substantial from them in November. You are right that in the season previews they were not expected to do anything...but then April rolled around and they had 50+ wins, so it's folly to pretend that they were still looked at the exact same way as they were in November.
I agree that two wins from the Finals is MUCH more than anybody would have guessed in November, but I don't consider them beating the Lakers and Clippers huge upsets or a monumental achievement, considering what they molded themselves into over the course of an 82-game season. Diaw was a stud that year. Barbosa, Jones and Thomas were like a lot of guys, they looked really good in the Suns system. That ended up being a very good team in a watered-down league where the only elite teams were San Antonio, Dallas, Detroit and I guess Miami, who very good in the regular season but got hot in the playoffs.