They said that it was a new project, yet they never mentioned a season 2.
imo, this will just be a OVA that shows us what happened after the ending and it will last for as long as 49 minutes tops.
And it being a sequel to the series is also doubtful but lord knows I wouln't mind to be proven wrong.

> Season 2 Episode 1 starts with Panty and Stocking eating breakfast in silence as they check their phones
>Brief walks in

Brief: …… Wait! Didn't YOU betray us and slashed Panty into 666 pieces?! Why are you here?! And how is Panty fine?!
Stocking: That's not canon.
Panty: Super not canon.

> Opening theme starts playing