It's not good enough, because there are instances where the project might die but they decide not to.

For example, if they are acquired and shuttered (like when fitbit bought and closed Pebble), if legal says they can't, or if the money needed to open source it after the fact is not available because they went bust and already owe creditors (you might need money to do a license review to ensure that releasing the code doesn't violate any third party licenses in software the project depends on).