I know the wonderful Siofra already covered this- yes! All previous challenges re-open every 10 weeks for the Catch-Up Challenge. You are welcome to participate officially at that time (and earn a shiny forum badge! 
).
On the unofficial side of things, even though past challenges are not longer currently running, all challenge posts are left visible to everyone to use as they see fit- you are free to use the resources and shared experiences there at any time you feel drawn to it 
I’m not sure if it is what you mean, but from what you said I think immediately of Chaos Magick- in which case, yes, there have been several challenges, group rituals, and other content around this particularly lawless and freeing aspect of the Craft (and will likely be more in the future too). Here are a few you may find interesting:
- Spells8 Lesson : Introduction to Chaos Magick
- Chaos Magick Weekly Challenge
- Group Ritual - July 14 : Chaos Magick in the Full Moon Light *coven members only
Blessed be! 