"It is not a goal to require programs to explicitly account for all null values that might occur; unaccounted-for null values may cause compile-time warnings, but not compile-time errors"
Unfortunately this will only be checked at the runtime.
Unfortunately this will only be checked at the runtime.
Worse, permitting this conversion at compile time means developers will ignore the warning, so we'll have actual codebases which include these conversions. Any later change to enforce nullability checking at compile time will then have a significant backwards compatibility cost.