Hi Timbo210,
No, you will not have to reinstall this add-on every time you download a new version or update of House Party!
The only time you will need to redownload or reinstall the Doja Cat Expansion Pack is if the Doja Cat Expansion Pack itself receives an update.
There was actually an update to the Doja Cat Expansion Pack recently, so that may be why you need to update it currently.
We hope this helps! If you have any further questions, our technical support team on Discord would love to help. You can reach out to them here: https://discord.com/invite/eekgames