Why they do not? Don't know.
I'm fairly certain that I know why. If you've followed +Vigano since he started out as a Traditional Catholic about 4 years ago now, and I know you have, you'll realize that he takes everything one step at a time. He realizes that he's a late-comer to Tradition and has been wondering how he can make a difference, attempting to discern why God called him so late to Tradition. I believe he sees it as his mission from God to open the eyes of the Conciliar conservatives, and in order to accomplish that, he can't lose them too fast. Had it come out immediately that +Vigano holds NO Orders to be doubful, and as an SV who denounces all the Popes since Pius XII, he would have lost his following among Trad, Inc. and the conservative types very quickly, thus defeting his mission.
So he's been taking it one step at a time, where each little step is palatable to the Conciliar conservatives and doesn't lose them completely, so then with each step he can bring along to the following step any who remain with him after the previous step. Bishop Sanborn, in his last video, said he may have been "impatient" and realizes that +Vigano is taking his time so that he doesn't "shock people". And it's not just about shocking them, but about losing them too quickly. This is a very deliberate pedagogical approach, similar to boil the frog, but more in opening their eyes little by little. If someone has been in total darkness, you can't just blast a spotlight into their eyes to help them see, since they'll just be blinded by the light (so the opposite of seeing), and will just turn away from the pain. But if you turn up the light just a little, let their eyes adjust, then turn it up a little more, let them adjust again, that's your only realistic hope of opening their eyes completely to the light.
I just think that a public annoucement of the conditional consecration would have been too much too soon for the Conciliar conservatives, many of whom have spent decades attending
Motu Masses, which +Vigano would thereby imply to have been of positively doubtful validity. Many of them also worship the ground on which St. John Paul II the Great Wojtyla walked, and +Vigano was originally "consecrated" by Wojtyla.
With every statement of +Vigano's, I pointed out, "ah, see this here, where he's implying the next step", and in every case I got it right. I could go back and find my old posts. But I saw what he was doing very clearly right out of the gate.
As you yourself cited, he's clearly IMPLICITLY laid out his next step in the last declaration, namely, that he's going to explicitly call Roncalli/Montini - Ratzinger Antipopes as well. From the principles he laid out, that conclusion is unavoidable, but he didn't say it in so many words, so as not to shock those who are still with him after having outed Bergoglio. With each step he makes, he also lays the groundwork for the next step, letting both the previous step and the principles toward the next step sink in and percolate. He'll take some time, perhaps weeks, perhaps months, to let it sink in, and then, from among those who are still with him, he'll make the next statement. I suspect that it'll be the step after that one where he'll come out to publicly announce the conditional consecration. In the meantime, he and Bishop Williamson have let it slip out in the dark recesses of the internet (i.e. here on CathInfo), so that people who may want to know can find out, but because neither have declared it, it remains in "ugly rumor among those schismatics on CathInfo" territory. Some might recall that it's what +Mendez referred to the ordinations of Frs. Greenwell and Baumburger, an "ugly rumor".
+Vigano is a brilliant man, and he knows what he's doing, and what he's doing is very deliberate, in the manner of a teacher trying to convert huge masses to Tradition, without losing them. So what good would he have done if he had immediately come out guns-a-blazing to excoriate the entire Conciliar establishment? He would have been preaching to the choir, the existing Trads, but would have exstinguished all hope of making new Traditional Catholic converts. Which is more important, to allow some Trads and dogmatic SVs to thump their chests, or to convert more souls to Tradition? It's the same approach he took with Trump. He knows Trump's psychological makeup and knows that coming out and excoriating Trump would have had no effect other than to have him double down against what +Vigano was advocating for. So he used his ego against him in an attempt to persuade him to move in a positive direction. +Vigano knows how people work and think, all part of his training as a professional diplomat, and he's put that into action here.
I saw the fruits of his approach in the penultimate video from Taylor Marshall. Not only did Marshall express sympathy for +Vigano's position, but I watched the livestream chat and found, to my astonishment, that 90-95% of the comments were in favor of +Vigano and against Bergoglio. My wife told me that today Marshall said that it was 85% in favor of +Vigano (my numbers were just rough guesstimate based on what I saw quickly scroll by). That is atonishing to take that many conservative Conciliar types and bring them along to where 85% of them support you in your declaration of Bergoglio's non-papacy. This demonstrates the fruits of +Vigano's brilliant approach here. +Vigano is actually using Bergoglio's own stated tactics against him. Tucho publicly stated that Jorge's tactic is gradualism in the hopes of making his changes permanent and unrevokable. Well, +Vigano is using the same gradualist approach, but to do good instead of evil, to convert souls instead of to destroy them.