How long until Opposing Source?

You have to make it at some point. Maybe Blue Shift: Source too?

Theres already a completely different team working on those. You’re barking up the wrong tree.

They don’t have to do anything actually. They’ve stated many times they will not work on Opposing Force or Blue Shift.

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.