Most probably, the newest worldsave will be loaded so nobody will lose anything 
Everyone will loose time what they have done before the new worldsave load , some may not notice this and for example craft 100 SS or level up a character , do a quest etc. etc. , then server crashes and rollback hits hard. Like for now everyone realizes there will be rollback so no pvp , because it will be just another hinkley fight.
These worldsaves should be more frequent.