Parmandur
Book-Friend, he/him
I mean, that's what they've said consistently for years, well before the Tasha's system. I see no reason to suspect otherwise.I readily accept the idea that game designers did not assign racial ASIs based on balance considerations, but I think it’s less likely that they don’t recognize any imbalance among the abilities.
That said, there aren’t objectively more valuable abilities. For a given class, there might be one ability that fully and clearly outweighs the others. For some classes, it’s more advantageous to have a moderately high stats in two or three areas than to have one ability maxed out.
Keep in mind also that D&D is usually played as a party-based game, and having characters with an array of strong points is better for the group than characters each focused on Dexterity (as an example).
If they were valued differently...ASI would have a difference based on which Atribute is being raised.