A bug of DELETE method of `wp_remote_post` in v4.6 beta4

I want to send a DELETE request that contain a JSON data to a server, in the stable version (4.5), I can do it like this:

wp_remote_post($url,[
	'method' => 'DELETE',
	'body' => ['tags' => ['example',],],
	'timeout' => 20,
]);

it is equals to:

$ curl $url -X DELETE -H "Content-Type: application/json" --data '{"tags":["example"]}'

It’s all works well in stable version

but in the beta version, it doesn’t work at all, first, the Content-Type header is not application/json, it send application/x-www-form-urlencoded, and the data is in url encoded type but not json, I edited the code like this:

wp_remote_post($url,[
	'method' => 'DELETE',
	'headers' => [
		'Content-Type' => 'application/json',
	],
	'body' => json_encode(['tags' => ['blog-'.$fsckeycdn_blog_id,],]),
	'timeout' => 20,
]);

but it still doesn’t work, the data is not send as POST method, but it is like GET method, the json data is send in QUERY_STRING, I can got nothing in file_get_contents("php://input")

I also tried this:

wp_remote_post($url,[
?	'method' => 'POST',
?	'headers' => [
		'Content-Type' => 'application/json',
	],
?	'body' => json_encode(['tags' => ['example',],]),
	'timeout' => 20,
]);

This works well, it not like GET method, I can got data in file_get_contents("php://input")

I think this is a bug, the function wp_remote_request also has this problem.