Does the LMA MSW solar solution imply the Dirac nature of neutrinos?

Operating with the bilarge neutrino mixing, we show that in the option of Dirac neutrinos the fermion universality – expressed by the proportionality of neutrino masses to charged-lepton masses – predicts $\mathrm{\Delta }{m}_{21}^2$ of the order ${10}^{-5}{\mathrm{e}\mathrm{V}}^2$, consistently with the LMA MSW solar solution. In contrast, in the option of Majorana neutrinos the fermion universality – introduced as the seesaw proportionality of neutrino masses to charged-lepton masses squared – predicts $\mathrm{\Delta }{m}_{21}^2$ of the order ${10}^{-8}{\mathrm{e}\mathrm{V}}^2$, what is consistent rather with the LOW MSW solar solution. Thus, the favored LMA MSW estimation of $\mathrm{\Delta }{m}_{21}^2$ might be a signal from the Dirac nature of neutrinos.