There are two levels of 'removing yourself':
1) You remove yourself as profile manager, but stay on the trusted list; this keeps the profile on your watchlist
2) You remove yourself entirely (as PM and no longer on the TL); this removes the profile from your watchlist
If you remove yourself as PM, yes, it will 'orphan' the profile. Even if there are a dozen people on the Trusted List, if there is no PM, it is an Orphan.