Keyed {#each} block's {:else} statement is rendering when it shouldn't

[PersonThing]

Describe the bug
Keyed {#each} block's {:else} statement is rendering when it shouldn't (if the array was empty initially).
Keyed {#each} block's {:else} statement is not rendering when it should (if the array had values initially).

To Reproduce
Click the first toggle - placeholder always shows.
Click the second toggle - placeholder never shows.
If you remove the key on each, behaves as expected, but not a solution.
https://svelte.dev/repl/fa1e979afd1a4928ac45e84fe48574c1?version=3.19.2

Information about your Svelte project:
Chrome 80
Windows 10
Svelte 3.19.2
Webpack, but REPL does it too

Severity
Minor - can just use separate {#if} outside the {#each}

[Conduitry]

This can probably be combined with #4536.

[PersonThing]

This can probably be combined with #4536.

Agreed - after noticing that one, I played with it more and found that whether it renders the :else depends entirely on whether the array was populated initially or not. It will always render if array had no value to start, and will never render if array had a value to start.

Better REPL:
https://svelte.dev/repl/fa1e979afd1a4928ac45e84fe48574c1?version=3.19.2

[Conduitry]

This is fixed in 3.20.0 - https://svelte.dev/repl/fa1e979afd1a4928ac45e84fe48574c1?version=3.20.0