No, that does not work.
Another trial with a picture from my Dropbox-album in the Archive:
This picture is just shared with my wife but picked from an "album" with the share-date as artificial name: 2017-06-08:
Even if that "album" was removed from Photos, the pictures stays here because it is stored in the special Blogger-album in the archive.
That is even more mysterious with the movie below: that still seems to be in an "album" named 2016-12-01 in the selection panel, but the album does not exist anymore on Photos or in the Archive.
But the movie does not play anymore...
Uploading a very small image (320px) from pc:
This gives the same size as when chosen Normal.
Does uploading a picture still work?
Yes and this is the full size 2048px image not resized in the blog.
This image is taken from a testalbum on Google Photos and the question is: what happens if that image in the testalbum is deleted?