Leosghost - 2:03 am on Nov 5, 2012 (gmt 0)
I personally know ( as in, have met them and seen their adsense accounts ) 3 people who have adsense accounts applied for , approved and opened for over 2 years ( in one case 4 years ) that they have never used ..never put the code on a website....
So zero traffic..the accounts are still open..so Google are definitely not closing adsense accounts due to low traffic..
They could ( because it is in their TOS in the thread that you linked to..) however that thread did not mention any accounts having been closed for that reason..and one poster ( respected senior member StoutFiles ) gave a specific instance of not having an account closed for that reason..
So there was no "rumor" in that thread..