This is a very grave concern.
I've read commentaries that declare the New Rite to be completely invalid. Those commentaries provide reasonable explanations as to why the authors believe the rites to be invalid and bases the conclusions on magisterial docuмents and theologians prior to Vatican II. I've not read any such commentary that was not well reasoned and compelling.
I've read commentaries that declare the New Rite to be certainly valid. Only one of these commentaries actually made a reasoned argument; most of them simply appeal to the emotions and say that the rites just have to be valid. The one commentary that used reason was way beyond my intellectual ability to comprehend.
All that being said, even the commentaries I've read and completely understood are based on comparative languages, the meanings of words in Latin, Greek, and other non-English languages, and some docuмents I have not access to. The commentaries against validity are only correct if the facts presented in them are true.
Thus, as far as I am concerned, the validity of the New Rites of Ordination (and, by extention, Consecration of Bishops) is at least doubtful. If the rites are indeed valid, the Church will have to make a reasonable case other than to simply say, "Of course, they're valid."