Well, I was able to find the grommet at the local u pull and pay. Grabbed it off of a 2006 and seems to match exactly.
Success! - Album on Imgur
Unfortunately I noticed when removing the harness from the grommet that there seems to be some rubber/resin potting material they used to seal the harness as it goes through the grommet. I was able to pull back the grommet carefully and get the harness to come out but I’m not sure I’d like to take that risk with the grommet currently on my 4Runner.
I’ll likely go the RTV route and as long as that holds up I’ll be fine. Probably just going to keep this spare grommet around as a last resort. It was $1.70 which is about %2000 cheaper than a new harness.