Hello,
I also bought this camera because the D-Link website (https://eu.dlink.com/fr/fr/products/dcs-8300lh-mydlink-full-hd-indoor-camera) says it supports RTSP.
The fact is that is doesn't. You say they removed the feature. I can understand this from a legal point of view, and products can evolve, even in the bad direction. But then advertising the feature is not fair. You can not "add" a feature in the advertisements and "remove" it from the product ! You could remove it temporarily for security reasons (this would be a really bad argument anyway), but then you have to tell when it will be back.
Best,