Beginning on October 13th, Google Drive is changing its Trash policies. After 30 days, files that you’ve trashed will be automatically deleted. Until now, those files have been stored indefinitely, unless you manually and permanently deleted them from Trash. There’s a good chance you’ll only be impacted by this change if you were using this odd policy to hoard files.
As The Verge notes, other Google products, like Gmail, already delete trashed files after 30 days. So this update will bring some consistency across Google’s products.