But didn't Harry say in an interview that they'd talked about it, although he'd designed it, and they'd agreed what she wanted, including the diamonds from Diana's collection? Either Meghan wasn't able or willing to be totally frank about what she wanted at that point, or Harry hadn't fully got into his 'what Meghan wants, Meghan gets' mode by then. Maybe a bit of both.
Re any future NDA drawn up in the hypothetical case of a future divorce, I hope the royal lawyers include a clause prohibiting fiction writing based on past events. I can imagine, after The Bench, Meghan moving into producing a blockbuster Barbara Taylor Bradford style tome where a poor girl marries into the elite but is then SILENCED by various evil onlookers over whom she eventually triumphs.