Not sure on the specific time frame, but generally when companies start adding purchasing options and regional restrictions they are nearing the release.
This depot was added to the FFVIII sub in the registry today:
Originally, Square added both FFVII and VIII to the registry, but once we leaked the FFVII release here on GAF they removed all of the information from the app.
New Depot was created this morning that includes both FFVII and FFVIII, possibly a Final Fantasy package for the upcoming Steam sale.
These were uploaded to the Steam registry a few days ago