Some assets are added to your watchlist automatically based on your platform activity — so you don't lose track of them.
Auto-adding means you'll receive ongoing notifications for important events on assets you have a stake in — capital calls, allotment confirmations, updates posted to the asset page, and so on. You won't miss something important because you forgot to manually watchlist it.
Yes — you can manually remove any asset, including auto-added ones. The system won't re-add an asset for an IOI or commitment that's already happened, but it will re-add an asset you currently hold.

