i cant think of one successful brand that has stayed the same and not evolved over time.
First off, do not read my comments as being anti change or anti evolution which is what many want to do. I am against change for the sake of change itself. That tends to lead itself to things like Maryland's monstrosities.
I can also say that I find nothing wrong with the uniform and/or helmets now, and also like other uniform or helmet ideas that are brought up. Disclaimer: I do tend to dislike most of the stuff that is "fan fiction", not because of the source itself (the fan), but because of the skill in the design (lack of any real design training, talent, or aptitude beyond the ability to "work" a computer).
You are right, brands and logos change. I am also right, change CAN hurt a brand if done poorly.
My marketing background, although a distant speck in the rear-view mirror, was littered with the lessons of the impact of poorly designed brand and image reconstructions. Changing a brand image can have both positive and negative effects and as such is a very slippery slope.
My whole point is this: My experience, and education, tends to suggest that the effect of a negative change in perception far outweighs the benefit of a positive change in perception. In other words with an instantly recognizable brand, such as Tennessee, the gamble will have little pay off if the re-design is good (there will be a barely noticeable impact on any quantifiable metric). Conversely, there tends to be a slightly larger negative impact if the re-design is bad (you could lose some fans and/or income from people who identify with the previous brand image strongly).
So as someone has said before "if it ain't broke, don't fix it."
What this all boils down to is the subjective nature of what is "good" or "bad" in a redesign. The only way to really test that is with expensive focus groups or by pushing out the new logo/brand into the market and seeing the effects.
If you want to have a conversation about change being necessary because the brand is in decline, that could be an interesting and valid discussion.