That would imply that bondholders believe they'd get more of their money back destroying Tesla, then some other form of bankruptcy outcome.

The point of converting to equity and becoming the main shareholders is not to bail out un secured debt from customers, it would be to stop from destroying your the goodwill and intangible value of the brand. If you burn customers for hundreds of millions of dollars including model 3 reservations, you'd only be hurting yourself.

As of right now Tesla is worth 50 billion dollars. Bondholders would be morons to try and ruin the company in Chapter 11. They have less of a chance recouping their money like that then they would by restructuring and trying to fix the business.