Your source shows an INCREASE of homeless people, but not necessarily an INFLUX, i.e. it's not clear whether the newly homeless are in fact "arriving" (from out of state) or have been prior residents who lost their shelter.
Anecdotally, I don't think I've ever met somebody who had a PLAN to move to California to be homeless there. But I've met a number of people who moved to California with limited financial resources and precarious employment prospects, and subsequently became homeless.