Earlier quoted context omitted.
Why would you want to add a delete keyword? Are you trying to add explicit memory management to simplify the work of the garbage collector?
One example would be game development, where people end up doing object pooling to avoid GC pauses dropping frames.
There are better ways to eliminate GC pauses than manual memory management (even ignoring the relatively new "pauseless" GCs). See the new RTSJ (realtime Java) specification here: https://www.aicas.com/cms/en/rtsj. Not that it's designed for far stricter requirements than games (cases where even microseconds of unexpected latency may result in actual life safety concerns).
Manual memory management is a good choice if you have both worst-case latency concerns as well as very restricted RAM and/or severe energy constraints (basically, the kind of applications that Rust was designed to handle).