What Does This Answer Mean?
I admit it’s a bit tricky, but we have the answer non the less.
it’s because the google raw data in analytics get fetched for all times.
if you don’t import data, the previous data is still there, therefore, creating an “all time data view”
so the answer to the In Views That Don’t Have Data Import Enabled, Custom Dimensions Values May Be Viewed For Dates Before The Custom Dimension Was Created is True.
If you want to avoid this issue you can set the data import so that your time is set from the time you want.