It is possible to have images and objects, which are larger than canvas size in photoshop:
Then why is it asking for crop if canvas resized?
Why should I loose information when I resizing just a canvas?
Is it possible to keep data?
In order to change the size without loosing pixels you actually have to use the crop tool but deselect the "delete cropped pixels" box:
You need the duplicate the layer before do the canvas crop. Because background doesn't preserve the image.