The scores they earn at the Senior B's only rank them among other winners at the bottom of the list, at least the way the announcement is written. The only scores that used to rank skaters among those on the PB list are split couples and comeback skaters, but they have to use scores earned at the same type of competitions (JGP/GP, championships, Olympics, WTT, etc.) that the skaters on the PB earned, not Senior B's (except the Olympic qualifier the season after the Olympics).
Verner is currently No. 37 on the PB list and, after Majorov's appointment and Balde moving into the Top Five, is second on the list to slot into the Top Five, after Zhan Bush. It's likely too late for that now, but his placement on the PB list puts him much higher on the alternates list than his Coupe de Nice win.
ETA: The new Top Five for Men is now:
With Menshov and Voronov competing at NHK, any withdrawal from the last three events is either one they are at, one that is back-to-back (Toyko to Paris), or one where there are already three Russian men. I suspect they only would be considered for a host withdrawal at RC. According to Wikipedia, Uzbeki citizens do not need visas to travel to Russia, and if Reynolds doesn't get his visa issues sorted or Gailhauguet pulls Joubert's second GP, maybe Ge will get a RC replacement spot, although the Russian Fed could choose Moscow-born and I believe Russian-speaker not to mention Balde.
For NHK or TEB, it would probably be Rogozine or Balde