Actually, a reading of the GIRM would indicate that standing after receiving Communion untill all have received is the norm. This is what prompted the dubium, by, I beleive, Cardinal George; the response from Cardinal Arinze was that the Vatican did not intend to so tightly or strictly regulate posture. The normal practice previously had been to kneel, but saying that one is to kneel seems to be as strict as those who insist that one stand.
There have been numerous other threads on this issue. In short, there is no comment in the GIRM concerning the posture of one’s hands - during the Our Father or at any other time. The issue has been around for over 40 years, during which the GIRM has been re-written twice, and at least one other specific document (RS) has been issued, all of them ignoring the very prevalent hand-holding during the Our Father. As Archbishop Chaput has said, it is not regulated, so it is not correct to say that it is not permitted; neither is it required. Those who wish to hold hands may, and should not be criticized by those who don’t; those who wish to not hold hands should not be required to do so as it is not mandatory, and should not be criticized for not doing so.
Holding hands during the Our Father is a sign of unity (and if you care to recite the Our Father slowly, you will note that all through it the words “we”, “our”, and “us” are used, all of which relate to a communal prayer). It has been argued that it is not the proper place to show unity, being just before the kiss of peace, and that arguement is well made. But to say that it is not permitted is flat out wrong. If holding hands is not permitted, because it is not mandated, then by the same reason, neither is it permitted to hold your hands in a traditional prayer posture - fingers interlaced or pointing upward. And we can both agree that postion is not tenable.