I think it is worth communicating about the server to invite groups of players to come and join the unused factions.
But the problem is that we have rumors of wipe without any actual date.
If the wipe is in august, it is worth telling people the date ASAP.
If the wipe is in september, it isn't worth telling people to come in august, then have everything they have built being wiped the next month.
If the wipe is in january, it is worth telling people to come, but you wouldn't attract the wipe-fans crowd and have less new features to introduce to those who left the cession earlier. But those who don't mind that would have the time to build their force without fearing the destruction of everything.