Hey @mitu thanks for getting back to me. It turns out the issue was not the wifi connection. I'll explain for anyone who might run into this stupid problem as well:
I'm working on a Mac (booooo) and when I opened the wifikeyfile.txt it opened by default in TextEdit.app. When I opened it and entered my credentials it looked a bit like this:
ssid="wifinetworkname"
psk="mypassword"
Unbeknownst to me, a non coder, it turns out there are two different types of quotation marks. WTF, right? See if you notice the difference between the two below.
Screen Shot 2020-11-04 at 10.17.37 PM.png
Yeah, unsurprisingly if you have quotation marks like those on the left like I did, when you try to <import wifi credentials boot/wifikeyfile.txt> it won't be able to read the text correctly.
The fix?
Go to the toolbar under edit > substitutions > smart quotes. Uncheck that option and you'll be able to type no nonsense vertical quotation marks that RetroPie will recognize.
Alternatively, if you open your wifikeyfile.txt in Sublime 2 instead you shouldn't have this bs problem. Seriously, I don't need fancy quotation marks here! I'm not writing a novel and if I was I wouldn't be using TextEdit.
Make sure you don't have a return below your second line. It'll be invisible if you don't have your text cursor on it so delete space until you only have two lines.
Sorry for the text dump but I figured this may save newbie like me a headache if they try making their own Gameboy Null 2 and run into the same issues.
To answer your question about the old version of RetroPie, it was part of a pre-made image that was recommended for the project, likely to save me the trouble of button config etc.
