The idea is not new at all, since already the mythicist Albert Kalthoff wrote so:
The Epistles, especially the four that bear the name of Paul - one to the Romans, the two to the Corinthians, and one to the Galatians - which make plainer even than the Gospels the dependence of Christianity on the death and resurrection of Christ, clearly intimate that this death and resurrection of Christ is not an individual experience, but one of the community. The death and resurrection of Christ is completely identified with the death and resurrection of the community.
(
The Rise of Christianity, p.137-138, my bold)
Unfortunately, Kalthoff didn't describe well the evolution of this personification, since I may imagine two possible versions:
there was already the cult of an angel called Jesus
this angel becomes the symbol of an entire group
or:
the group as first act projected itself in an angel without name
at the end, the name Jesus was given to a such angel otherwise forever anonymous