Even though Google has effectively launched its free tier of Stadia, Stadia Base, it's no longer calling it that.
Earlier this month, Google announced it would offer two free months of Stadia Pro, which is normally a paid subscription service costing $9.99 per month.
As a part of that announcement, Google added that games purchased as a part of the free Stadia trial would remain accessible even for users who canceled their subscriptions after the two-month free period.
Users signing up for Google Stadia also now have an additional option at the end of the process, allowing them to opt-out of the two-month Stadia Pro trial and simply begin purchasing games through Stadia without signing up for Pro at all.