Oops! I most definitely did NOT reinsert the cable into a closed connector. We can only wonder why Apple instructed this step to be counter-intuitive. I’ll pay closer attention to any weirdness that may arise, but the MacBook has been traveling and performing as it should; I’m going to avoid reopening the case, as easy as it is, until I have a good reason to do so. Thank you for replying and updating the guide!
I’m pretty sure I understand the instructions here, but I had to think about it a little longer because “… must remain closed when the cable is reinserted during reassembly …” was not clear to me right away. The retaining flap I discovered, is super delicate, and hence my paranoia, so I wanted to point this out in case anyone else felt like me: ''''Is it correct to assume that your instructions could be interpreted as:
“After disconnecting the cable, close the retaining flap for now to avoid damaging it. When reinstalling the cable, flip up the retaining flap once again, realign and slide the cable with gold contacts facing down.”
I bent the USB-C corner of the lower case from a short drop onto laminate flooring, so in I went to shape it so the edge wouldn’t snag or scratch things. I am typing on my MacBook that received the body work.
Thank you for your guidance!