I had the same question and I believe they are not, at least in the MNI152NLin2009cAsym space.

The Schaefer team provide CSV files with all updates here

https://github.com/ThomasYeoLab/CBIG/tree/master/stable_projects/brain_parcellation/Schaefer2018_LocalGlobal/Parcellations/Updates

I looked at Update_20190916_component_name_changes.csv and for example, 400Parcels_17Networks parcel 65 "17Networks_LH_DorsAttnA_SPL_1" becomes "17Networks_LH_DorsAttnA_ParOcc_2".

But in tpl-MNI152NLin2009cAsym_atlas-Schaefer2018_desc-400Parcels17Networks_dseg.tsv parcel 65 is still referred to as "17Networks_LH_DorsAttnA_SPL_1".

Should the updated Schaefer atlases be added to templateflow as new atlases, or should the old ones in templateflow just be replaced with the new ones?