Not sure if I understood your post, but it is nothing to do with Developer Console incident.
After created a new Messaging API bot, in Developer console, the webhook URL is empty, "Use Webhook" toggle is not shown.
There is an option to enable Webhook on Official Account Manager even webhook URL is empty, but it doesn't take any effect, looks like a bug.
To enable webhook, I need to call set webhhok endpoint to set URL, once it is set, it will appear in Developer console, and "Use Webhook" toggle will appear but disabled, I need to enable it here manually.
So my question is, is there any way that I can enable "Use Webhook" by API? The manual step above is really annoyed.
(the answer is same as https://www.line-community.me/ja/question/62c2f97256453b191e43eef7)