.m/.wl will not have Cell[...] expressions
But those text files still will reflect whether or not you (while editing in the front-end) set cells as Initialization Cells.
You can confirm this yourself by opening .m/.wl files in a text editor. First create a new .wl file in the font-end, set its cells as not-Initialization-Cells. Save it and view in a text editor. Now back in the front-end, modify the cells so that they are Initialization-Cells. Save it again, and view it again in a text-editor. It makes a difference, and that difference is what I described in the original post:
To cause Get to perform as documented, it's necessary to set all cells
in a .m or .wl file as Initialization Cells, but this is not disclosed
by the Mathematica documentation.
Then you tell me:
Hopefully, you will be able to do some research in the Documentation.
Much of this is explained there.
And I likewise hope you will be able to do some research in the Documentation, and if you do that, you will see what Wolfram discloses about the importance of the Initialization-Cell setting while editing .wl files using the font-end:
http://reference.wolfram.com/language/ref/menuitem/SaveAs.html
Wolfram discloses nothing about the importance of the Initialization-Cell setting while editing .wl files using the font-end. It is an undocumented secret concealed from new customers. It is a misleading deficiency in the documentation. You are saying the emperor's clothes look great, when they really do not look great. You have the luxury that your livelihood doesn't depend on the quality of the Mathematica documentation, but Wolfram employees don't share that luxury. Deficient documentation, if it persists, will hurt sales.