Atmospheric planets does not equal planets with life.
First step is to release planets like Mars and maybe Venus (which is probably a bit more complex), along with gas giants. All of these will be the next batch of landable planets Frontier release.
Planets with life are much further away.
I think its an issue of hardware as well.
With this game on Consoles (even with the new PS4 4k and XBone 4k) there is a processor cieling and with Brabens demand for high quality (which i personally agree with and respect) i think the high CPU/GPU demanding worlds with life and atmosphere are a while away yet.
But Barren Atmposphere worlds... that i dont expect to be a long way off.
Im betting Barren Atmosphere and Space legs be season 3.