Were these angels newly created or all veterans of previous kalpas (universal cycles)?

There was a mix of both involved with respect to Milky Way as well as the other worlds dispersed throughout the universe. This is somewhat analogous to the creation of the divine human as an extension of their souls to be a new version of life form that previously did not exist. The current iteration of the universe was intended to surmount prior difficulties with the Free Will Experiment and as such, new types of angelic consciousness were created to help maintain better order and a more positive outcome.