There is a difference from no changes at all, and not changing the direction of design intent.
I have used this example before. When they remade D2 into D2 resurrected they didn’t change it into a first person shooter, they kept the origional games design intent of hoe the game was to be played and how players could interact with the game.
Wotlk Dual spec goes directly against how tbc design intent had intentional consequences for regular spec changes. With a cost and location inconvenience.
A CD based dual spec that can only be done in a capital city does keep those design intentions in mind and I am not really against dual spec with intentional restrictions and consequences that keep it in line with the design intentions and goals of tbc. But a full wotlk version of dual spec is not something that should be in tbcc as it goes the opposite direction of the design intentions of the original game.
And against, design intentions are not the same thing as the exact design. This isn’t about dual spec being a change, it’s about wotlk dual spec going the opposite direction of the intentions of the design of tbc.
We have proof of the design intentions of tbc on this subject, you can chose to read it if you want.