you cannot transfer your sponsorship before completion AT LEAST 1 year with the same sponsor (sometimes 2 years are required), regardless you have a NOC or not.
Getting a NOC - ask about it your Company BEFORE signing the contract, simple.
even if your contract term is completed, you still will need a NOC letter to join another company.
rumors are rumors.. you ask us how exactly it will work, while admitting that it's only rumors so far.. doesn't make sense to me..