I just realised that Sydney probably got the idea of her wigs by Junes power and wanting to put her old self behind her despite her being frozen in time. Also I think she uses wigs because the series has talked about Sydney’s and Serena’s hair as an important similarity between them and how that’s why Serena told Sydney to cut her hair. I think that for Sydney to stop being frozen she might have to let go of the last thing connecting her to her past which is Serena and she hasn’t shown any sign of letting go any time soon so…