Yaki plot and Xenon extinction

[pref]

Are xenon as easy to get rid of like around release of the game?

Want to finish the Yaki plot, i'm just afraid that if i exterminate the xenon over there they might be quickly gone from the universe altogether.
Is there a way to ensure that they remain a threat to factions?
Or are they more resilient now?

Want to build up a nice empire until 7.0 and timelines arrive, and it would be a shame to not see the new xenon ships in action. Really liked some of the X3 designs.