Provavelmente não.
A descrição de Tolkien do resultado é descrita mais completamente na Carta 156, onde lemos:
For in his condition it was for him a sacrifice to perish on the Bridge in defence of his companions, less perhaps than for a mortal Man or Hobbit, since he had a far greater inner power than they; but also more, since it was a humbling and abnegation of himself in conformity to 'the Rules': for all he could know at that moment he was the only person who could direct the resistance to Sauron successfully, and all his mission was vain. He was handing over to the Authority that ordained the Rules, and giving up personal hope of success.
That I should say is what the Authority wished, as a set-off to Saruman. The 'wizards', as such, had failed; or if you like: the crisis had become too grave and needed an enhancement of power. So Gandalf sacrificed himself, was accepted, and enhanced, and returned.
Então, a partir disso você pode ver que a promoção foi um resultado direto do sacrifício, e o sacrifício foi necessário para que a "Autoridade" (ou seja, Eru) pudesse intervir.