I see. Too bad, because it is a perfect opportunity to flesh out that era. Even if/when one of our authors writes about the 2230s again, s/he won't be able to use the most iconic characters from that era.
It won't be a "forever" ban. Be patient.
Who are you counting as "iconic", apart from Robau? 'Cos George Sr and Winona Kirk have appeared in several ST novels.