I disagree that they are right (from a shareholder perspective) to deauthorize the OGL 1.0a. Look at the blow back they've received because of it. So far, it's been an absolute fiasco for them.
If I were Chris Cao, and I wanted to achieve his goals, I'd probably take the approach of boiling a frog. Leave the OGL 1.0a in place, but slowly move the D&D ecosystem far enough away from the original 5e rules that the 5e SRD becomes irrelevant to the new ecosystem. It would take longer, but they'd be able to build their walled garden with far fewer people noticing.
I feel a little gross having typed that.