Per PFT: Saints switch Taysom to QB on roster designation.

To be fair, even Ross is speculating at this point. Until Sunday's gameday roster gets rolled out, or until announced otherwise, no one really knows the plan for Week 1.
FWIW, he wasn't speculating about how the QB rule works. But, you're right. he was speculating about how the Saints might take advantage.

Much of this thread is about how the 3rd QB rule works. That he covers without speculation.