As far as I can tell, the US Bishops Conference has never officially addressed the matter. Even though it has not be officially addressed by the Bishops Conference does not mean its a free for all. The general principle for liturgy is:
Therefore no other person, even if he be a priest, may add, remove, or change anything in the Liturgy on his own authority.
Sacrosanctum Concilium 22,3
While its one thing if a married couple or family spontaneously decide to hold hands amongst themselves, no one can mandate that another person in the congregation hold hands with someone else. To do so would be to add a prescribed position that is not present in the rubrics (which would violate the general principle of liturgy).
The liturgy belongs to the Church, not the priest or the congregation. Neither the priest nor the congregation have the right to invent and insert into the liturgy their own novelties or force others to adopt them.