The implicit or electrostatic doping as you put it is similar to explicit actual dopant atoms in that results in a similar shift of the Fermi level, which in turn is a result of charge redistribution, so yes it should be able to describe the depletion region. It does not however, naturally, add any dopant scattering as real dopants would, but if that is not a major concern (and other effects like dopant clustering or position-dependent effects) then I would say that the electrostatic doping provides a physically equivalent picture as real dopants, but with major benefits such as the ability to handle any (and in particular low) concentration without making enormous supercells plus also the possibility to use semi-empirical methods which do not have parameters for the dopant atoms.
