My gosh it's like the world is one big rumor!
the weight , damping and radiation of whatever that particular piece of material is will dictate whatever tonal effects it has much more so than the species.
The only real differences to me would be based in "feel", obviously there is more pronounced grain in Rosewood, which those who really dive into the fingerboard may not like,that can be mitigated with certain grain fill methods however.
And then I suppose the Janka hardness factor may come in a bit related to longevity,but not really too much, as it does have frets.
Janka hardness for those who do not know,is a test used to identify a species resistance to denting or hardness
A 1/4" ball bearing has 1000 lbs {something like that} set on it, the amount the ball bearing depresses into the wood {how deep is the divet} tells you how hard the material is. Ebony is way harder than even the hardest Rosewood species in general.As Bruce pointed out, there are many species of Rosewood.
Much of this data will have variation in the results.
Related to fingerboards, and necks in general. Without getting into all the ugly acoustic science and principles related to structural building. What really matters is weight distribution.
Basically we want the weight to mathematically taper a gradient from the body end being heavier moving to the headstock which we want to be lighter.
What I look for are pieces of material that do not have equal volumetric mass, and or a stick of wood that when balanced at the center point will like a teeter totter tilt to one side or the other....the heavy end gets installed towards the body, the light end goes up near the headstock. And the same goes for the neck material.
To me, this will dictate "tone" related to this particular aspect more than anything else.
http://www.bellforestproducts.com/info/janka-hardness/