No. They can appear to whomever they want (need) to
Disembodied voices are Force ghosts too, and Rey interacted with at least: Obi-Wan Wan Kenobi, Anakin Skywalker, AshokaAhsoka Tano, Kanan Jarrus, Luminara Unduli, Qui-Gon Jinn, Aayla Secura, Mace WindiWindu, Adi Gallia, and Yoda.
Rey metdid not meet a single one of them. She heard Luke too, but had met him while he was with body, reinforcing that Force ghosts can also interact with people they already knew.