It was supposed to be released on July, but it was pushed to October due to "various circumstances".
Anyways, without further ado, here's the recent teaser trailer for OreGairu.Zoku OVA that, according to the sources, will cover the Volume 10.5 of the Light Novel series.
About Season 3
Season 3 would have to wait in the near future as Wataru Watari, the author of the LN series, is currently working on the anime "Qualidea Code " as a scriptwriter. He's also going to be involved in another upcoming anime, "Gi(a)rlish Number ", which is set to be aired on October 7th, also as a scriptwriter. Also, according to other sources in Kyakka, it has already been scheduled that the Volume 12 of OreGairu light novel series is already in the works, but due to Wataru-san's limited timeframe, the volume 12 of the LN is currently onhold. So I guess the materials for Season 3 is still left onhold until Watari-san starts writing for the LN.
Anyways, please continue to SUPPORT the Light Novel! for the sake of Wataru-san and for the 3rd season!!!