Update for anyone interested. I picked up the parts today and installed the HEPA filter on my 2020 Model Y. Here are some thoughts:
1) I had zero problems getting the parts. Simply requested the parts through the app, schedule a service appointment for next Monday, and then followed up early to see if the parts were in. They said they had the parts and I could pick them up whenever I wanted.
2) The new filters come with metal inserts in the bolt holes. I guess it's to add more reinforcement. Someone else posted about it earlier and I also had to remove these inserts in order to make the holes bigger and line up. I wouldn't be surprised if Tesla adjusted the holes very slightly for new models.
3) I drilled new holes for the alignment pins. The hardest part about this was lining everything up and making sure I drilled in the correct place.
4) I used rivnuts since my car doesn't have existing threads in the hole. This was a very easy process and used a tool bought on amazon to install it properly.
I created a new mobile service for a couple of weeks from now. I told them that I need to have the car software updated to recognize the HEPA filter and enable the bioweapon defense mode button. We'll see how that part goes. The airflow is definitely lower with the new filter installed, but it's certainly no big deal. With the recent software update, we can now choose between low, medium, and high when the air is in auto mode. So I'll probably just leave it on high assuming they won't update my car to recognize the new HEPA filter.
PS this post was not proofread prior to posting and I'm a little loopy at the moment from smelling fumes after staining some wood flooring. Sorry if I said anything that makes no sense at all!
Here's a picture for anyone interested