Thank you, Betty, for your kind comments. It was a fun knit, to be sure! And one I will probably attempt again someday.
I just went and tried it on again (cause I completely forgot whether I unbuttoned it or not the other day), and I don't need to unbutton it to pull it over my head. Of course, I used a cotton blend yarn, which is very stretchy, too, so that helps. However, I will also say that my neckline is large enough to fit over my head without much (if any) of a stretch.
If you look at the pattern, you will see that it has you working back and forth in rows to allow for the button flap. Obviously, you could just make this completely in the round as a regular ol' top down raglan and then sew the buttons on for sheer decoration (or for sheer torture, depending on how you feel about sewing--with me, it's the latter).
I hope that helps. Will you be making one? Would love to see your rendition!