The way I read this, it would appear that you're suggesting (and therefore agreeing...) that, with mass-produced instruments, which most of us play, there is, indeed, no reliable way of telling from tone alone what the finger-board is made from, nor the body, nor which strings are used etc. It may be, in esoteric isolation, that expert ears can identify woods, and hone the instrument to the way required; not many players are concerned, I'd suggest. For an enormous chunk of the population of the planet, including a vast number of bass players of all persuasions, a bass is a bass is a bass; end of story. A light-coloured or darker neck is, I maintain, about as important as the material used for the strap. Leather, nylon, string..? Not such a big deal as all that.
Disclaimer: I'm a drummer; what would I know..?