The sequel trilogy being about legacy, it is interesting to have the characters be left to interpret for themselves the actions of those who preceded them.
The problem being that the original trilogy already set up the fact that force ghosts interact with the living when they feel a need to.
Hell even TLJ had Yoda.
Anakin’s ghost appearing in the end of RotJ locks in what you do with a Skywalker descendant who is worshipping Vader.
Also funny that you mention “legacy”, since that comic series DID have both Luke and Anakin’s force ghosts talk to an edgy Skywalker descendant.