This kind of happens in a lot of long-running shows and movies...Doctor Who (most recently with Capaldi), CSI, and films such as Star Wars and the James Bond series recast supporting roles all the time. For example Joe Don Baker, who played the villain Whitaker in The Living Daylights appeared two films later as a good guy, Jack Wade.
And let it be noted that Xena was the third
character Lucy Lawless played on Hercules.
Didn't seem to bother anyone that the show had already used the same actress twice before . . . or stop audiences from embracing the character.