Although O-1 visa holders are not in the same “dual intent” category as H or L visa holders, they do have a special provision per 8 C.F.R. 214.2(o)(13). It in essence states that an applicant cannot be denied O-1 status for merely filing paperwork that would indicate an “immigrant Intent”. Keep in mind however, those with a pending I-485 would need advance parole in order to keep their Adjustment of Status processing if they need to depart while it is processing.
Here is the code for your review.
8 C.F.R. 214.2(o) (13) “Effect of approval of a permanent labor certification or filing of a preference petition on O classification. The approval of a permanent labor certification or the filing of a preference petition for an alien shall not be a basis for denying an O–1 petition, a request to extend such a petition, or the alien’s application for admission, change of status, or extension of stay. The alien may legitimately come to the United States for a temporary period as an O–1 nonimmigrant and depart voluntarily at the end of his or her authorized stay and, at the same time, lawfully seek to become a permanent resident of the United States.”