Cool, nice find. But let's be honest about a couple of points Sully made back then:
Sully doesn't exactly sing SJ's praises. When he does talk about his value, it's in the context of Chan Gailey's offense. Perhaps the point he's trying to make now is that, with Chan gone, his value has gone down tremendously. And another one:
Again, not exactly singing his praises, and when he does talk about his value and ability, it has to do with the chemistry between him and Fitz. Who, like Chan, is no longer here.
Point being, perhaps the things that made SJ so valuable in the first place (Chan and Fitz) are now gone, reducing his value to the point where he is no longer an important asset, and thus the reason for Sully's change of mind.
Of course, it certainly would have been better to point this out rather than to say he was against the re-signing of SJ. But I'm not sure I would call it a complete 180.