Diamond open access and fully OA publishers might do that (maybe as an add-on service on top of LOCKSS or Portico), but the Big Five definitely do not want to do that, because they sell bulk access services at lofty prices.
There's no use expecting anything from the publishers. Universities and independent archives need to do the job.
That's wonderful! I didn't know that! But, as I read it, the basic arXiv license only permits the arXiv itself to redistribute, not anyone. So it's not clear that participation in the torrent is legal, particularly after the arXiv is shut down.