From what I read around online, you are right... however, it doesn't matter anyway because I have gotten really put off of modifying my phone because the first one I had completely died and then I got a new one. I rooted that one and added root only apps like barnacle and other stuff and I completely lost all service. My phone was stuck in airplane mode and it was impossible to turn off.
I flashed via odin and it took me back to EF23, but I still had no service. superuser was still on there, so I spent like 4 hours trying to figure out a way to get it off and unroot my phone because I knew I was going to have to take it into a Sprint repair place to get it fixed.
Finally I figured out I could flash via odin to EF23, root the phone and remove superuser via ADB, then update the software to EF27 which removed the root.
My life has been hell for the past week haha.