SHF has always claimed to have had assistance for the Sacrament of Confirmation and holy oils from retired or current bishops from the Novus Ordo, so I would think they do consider the New Rites in general to be valid (if validly celebrated).

That is a stretch.

To my knowledge Servants of the Holy Family has considered the Novus Ordo to be “questionably valid” and does not recommend for laity to participate in it, even when no other Mass is available. 

This is a separate topic from whether someone is a legitimate bishop or not.

Mpundu is not a Thuc-line bishop.  So far as I am aware, he was ordained a priest, and consecrated a bishop, within the mainline post-Vatican II framework.  I would expect the usual debate about the validity of post-Vatican II orders, which he would possess even if he consecrated Bishop Ward using the traditional ordo.

Still doubtful though for different reasons.

When Christendom is restored they will all come to our Bishops to get conditional ordination and consecration.

Show me Bishop Williamsons baptismal certificate, dork.

Thats a negative doubt.
I'm talking about a positive doubt.