Netflix licenses (anime)?

Is it more common for the licenses for certain series on Netflix to expire, but they are reintroduced into the program months or 1-2 years later?

Yes, Netflix has already done that with several series. But I wouldn't trust Netflix to buy it and would watch it on Anime on Demand, Chrunchyroll or Wakanim.

Yes even all the time. If you want to watch anime, don't get Netflix. I recommend AOD or Wakanim. You can even watch Cruchyroll for free.