Does temporary units earn hold points?

Yes, units with the Temporary keyword can earn hold points.

According to the rules, Temporary is a keyword that triggers a specific effect at the start of the controller's Beginning Phase (Rule 742.1.b). It does not restrict a unit's ability to participate in game actions like holding a battlefield or scoring points.

As long as the unit is on the board and meets the requirements to hold a battlefield, it functions like any other unit. It will continue to contribute to holding a battlefield until the Temporary trigger resolves at the start of your Beginning Phase, at which point the unit is killed.