Not true. There are many other contributors that the FB wood type is zero or in the noise level. It has more to do with the slot width vs fret tang ratio, the style and size of the barbs, how it was installed, and whether it's under stress across the radius. There are hammering techniques that will leave the fret relaxed in the slot. For example if you snapped your fingers and the fretboard was completely vaporized, what would the frets do? Would they go "ping!" and spring to different, distorted shapes? Or would they stay in the same radius as the board? Those things contribute more to fret spring.
The best part though, is that if the fretwork is decent, a little slip of the thin CA into the slot pretty much guarantees the frets to stay down for an eternity. (at least I think, I'll have to get back to you in forever)