Yes and no.
Yes, because uploading/dowloading/creating albums via the old Picasa Web Data API will have changes reflected to the new Google Photos interface as well.
No, because regardless of the user setting, all photos uploaded through this old API will count against the user's storage quota (even if you upload using the desktop version of Picasa!).
The Google Photos backup tool does some pre-compression before uploading photos, and only this (proprietary, undocumented) way of communicating with Google's servers provides access to the unlimited storage.
