There was no debate for Sister Flame: she was going to make and play her old character... and is.
I did the "both" approach. I remade two of my old mains right away and then made a few new ones: Doctor Detroit as a healing support and John Wyck....
My youngest daughter, who was 9 when the servers shut off, made a brand new character. Her old character was Fencebolt, an electric/electric blaster that she enjoyed. She goes where angels fear to tread and plunged into a brand new character who is a dark/dark dominator. She is rocking it hard and amazes me by how quick she mastered her new powers.