Not so.
From
vatican.va/roman_curia/pontifical_councils/laity/documents/rc_con_interdic_doc_15081997_en.html :
“Neither may deacons or non-ordained members of the faithful use gestures or actions which are proper to the same priest celebrant.”
It’s not an affirmative direction, but it definitely says what NOT to do.
You have not proved anything.
For starters, the discussion is about holding hands - and that is not a “gesture or action which is proper to the priest celebrant”. So the note does not apply.
As to another gesture, the orans position, you lose on two points; this prayer (the Our Father) is not a prayer of the priest, but of the community, and not only has Rome approved it as a prayer posture of the laity (see above in the thread) , but also the bishops of the US considered requesting permission of Rome. I know that not all the bishops were in favor of that, but I kind of think they were aware of the point you make. It would be simple to say that the motion failed because other bishops saw it is a unique gesture of the priest, but without polling all of them, that is just a wild guess. It passed for Italy, so apparently Rome does not think so. And I am more likely to follow what Rome thinks.
I am not promoting holding hands; I frankly don’t care one way of the other. I have endured it for 50 years, and it doesn’t make my socks roll up and down either way. In charity, I would not refuse to hold hands with someone else with the exception of this last Sunday - Mass was three handkerchiefs long as I have a strong cold. Nor would I ever push someone else to hold hands. It is a fact of life that some people are uncharitable - sometimes they are the people pushing someone to hold hands, and sometimes they are the people refusing to do so. For someone who has a phobia about germs, I can understand. This issue has been brought up in Catholic Answers Forum numerous times, and frankly, some of the answers have reeked of a lack of charity.
For 50 years, give or take one or two, people have been holding hands during the Our Father. and for just about as long, Rome has pointedly ignored the matter when they have had several specific opportunities to do so; and in fact, have addressed the issue in Italy contrary to those who insist that it is against the rules to do so.
Maybe all of this angst could be put to better use by doing something positive to end abortion, or to get the 80+% of those between 18 and 30 to go to Mass. Just sayin’.