TTT's interpretation makes no sense, not least because Johnson has no control over the situation. If he refuses to send the letter requesting an extension then he is breaking the law, and would at that point be thrown out of office, and the matter is no longer in his hands. If he sends the letter then it's the EU's decision whether or not to grant an extension. If it does, it's out of his hands. If the EU refuses an extension, that is still out of his hands -- and, what is more, I think it likely that there would be a majority in Parliament for revoking Article 50, or at least passing the necessary legislation, in that circumstance.
In every scenario, therefore, Johnson has no control over the question of whether or not there is a No Deal exit. Instead, he has bent over backwards, and abandoned most of his red lines -- including some he resigned over back in the day -- in order to secure a deal, any deal, that he can claim his own.