In_reply_to_status_id is missing



The tweet “A” with id “726712058381799424” is a reply to the tweet “B” with id “726711536874602497”. But since 21st October 2017, when asking for “A” via the API
the following data is returned:

"id": 726712058381799424, 
"id_str": "726712058381799424", 
"in_reply_to_screen_name": null, 
"in_reply_to_status_id": null, 
"in_reply_to_status_id_str": null, 
"in_reply_to_user_id": null, 
"in_reply_to_user_id_str": null, 

This is strange to me, as even if “B” was deleted at that point, the API should still return the information that “A” is a reply to “B”, thus I would still expect that the returned data looks like this

"id": 726712058381799424, 
"id_str": "726712058381799424", 
"in_reply_to_screen_name": "emo boy 14", 
"in_reply_to_status_id": 726711536874602497, 
"in_reply_to_status_id_str": "726711536874602497", 
"in_reply_to_user_id": 3136364444, 
"in_reply_to_user_id_str": "3136364444", 

(Or, if returning the user’s id and name is too data sensitive, then at least the “in_reply_to_status_id” should be returned.)

I tested this for other cases, and noticed that the “in_reply_to_status_id” of deleted tweets are indeed returned. Why is it here not the case?