Boeing fuel switches safe, regulator says after Air India crash
bbc.com
bbc.com
There's a very small new development here, which is just that the BBC emailed the regulator, and the regulator confirmed that they didn't believe there was a flaw in the locking mechanism.
This obviously comports with the hypothesis this was a deliberate action, but the regulatory stresses we shouldn't jump to conclusions & that they haven't yet determined a cause.