Follow Up and Clarification
Here's the ultra-conservative approach and I think it may be the safest way to look at it.
If he enters the U.S. under Advance Parole, he does not terminate his H status, but enters as a Parolee. His H status is said to be dormant and the Parolee status overrides the H. This means that if he enters as a parolee, but then seeks to revive the H status, he would have to depart the U.S. and reenter using his H (if such status is still valid). He can file for an extension of H-1 status and that would revive the H-1 status.
Considering detailed questions like this is one of the reasons that I started to post, and continue posting, to this forum. It seems as if the above would have no effect on the H-1 holder as a practical matter but could have a considerable effect on H-4 holders. This is particularly true since the Service will not consider a paroled adjustment applicant's failure to obtain a separate employment authorization document to mean that the paroled adjustment applicant engaged in unauthorized employment by working for the H-1 or L-1 employer between the date of his or her parole and the date to be specified in the final rule. I see no difference between the H-1 holder who is paroled into the US and the H-1 holder who enters on an H-1 other than the notation at entry. The H-1 holder can work for the H-1 sponsor without obtaining EAD and can extend his/her H-1B status. There is some question as to the effect on H-4 and USCIS/BCIS/INS has made no pronouncement on this.
My advice on something like this is to always speak to your immigration attorney for specific advice since this area is complex, fact specific, and as previously discussed, subject to change.