I'm sure others have said this, but my guess is that Huonder will consecrate any new bishops alone--the other SSPX bishops will not be co-consecrators--so that as the valid bishops and priests of the SSPX die, the only priests of the SSPX that will be left will be priests whose orders stem strictly from the New Rite. In the end, the SSPX will have all the ceremonies but none of the sacraments.
But wouldn't that be uncanonical? I'm assuming that the four SSPX bishops consecrated in 1988 were only consecrated by two bishops, not three, simply due to a third bishop not being available.
It would be awfully hard to justify consecrating without three bishops, if three bishops were indeed available, as they are in the SSPX at this time. Here's what the Catholic Encyclopedia says:
https://www.newadvent.org/cathen/04079b.htm