Call to Battle

No, because Call to Battle requires the player to choose the move destination, so the restriction on valid destinations applies directly.

When a spell or ability has the player choose a move destination, that destination must be somewhere other than the unit's current location.^{[355.4][355.4.a]} Call to Battle has the player choose both the unit and the battlefield, so the chosen battlefield cannot be the unit's current location. A play that cannot satisfy this requirement cannot be put onto the chain.^[355.8]

This contrasts with Flash, which specifies its destination — base — rather than requiring the player to choose one. Because no destination choice is made when playing Flash, this restriction never applies, and a unit already in base is a valid target.