It's common for middle eastern carriers (QR, EK, EY, Turkish, etc.) to provide accommodation, not in terms of "overnight" connection but for connections like more than 8 hours, given that the connection is the shortest on schedule and that the travellers are paying certain fare sub-classes.

I can understand why the OP has this expectation / question in mind, if he is flying with middle east carriers (in fact he did have such experience with RJ). Bear in mind that middle east carriers are mostly network carriers with a significant portion of connection traffic .

Having said that, LHR is usually well served by airlines with multiple daily frequencies, so short connections are not really necessary (unless they are chosen).