Those two things contradict really, being a newbie and a recognized member of the community. So it's safe to assume that no newbie has no chance of becoming a merit source.
newbie just need 28 days and 1 merit to achieve the next rank and follows but when someone is trying to contribute something towards their community they will get the recognition very soon so it will make them to be one of the recognised member in the community, if full member can be a merit source then a member can too if they actually deserves it.