Stonehenge is dated to 3,000 BC, and what we know about burials at that time goes against the above conclusion.
How we bury our dead is a direct reflection of how we perceive our spiritual life. So the burying of our dead in a separate place - deemed to be consecrated and away from everyday life - is a comparatively modern phenomena in a lifestyle where religion is just kept for Sunday-best.
Ancient man did not have the same separation between material and spiritual life in his mental cosmogony.
We can see remnants of this behaviour today in our oldest tribes. The Barasana Indians, who live in the remote and densely forested Vaupes region of Columbia, are a great favourite with anthropologists because they are often cited, along with the African San people, as still living in the way that the ancients did.
The Barasana live in 80 ft x 40 ft longhouses, and just like Neolithic structures of Catal Hoyuk and Ain Ghazal (as well as those of later Harappan civilisation in the Indus valley) their living quarters show that they like to keep their dead around. Their longhouses are also the settings for their shamanic rituals - again, the spiritual and the material are not separated into different buildings.
This drawing is from Christina Hugh Jones, who along with her husband, Stephen, have written extensively on the Barasana:

From Inside the Neolithic Mind by David Lewis Williams and David Pearce:
When Sir Mortimer Wheeler and others began digging up the Harappan civilisation in the Indus valley (c. 3,000 BC), they found that in the earlier phase, bodies were buried under the floors of the houses.
Death leads to the lower realms of the cosmos. Graves are dug into the floor and are thus in the underworld. The body, in a foetal position and with a gourd over its face, is placed in a canoe that is cut in half and doubled over; it provides the deceased with transport through a subterranean river. Geraldo Reichel-Dolmatoff, who studies the South American people some years before the Hugh-Joneses, pointed out that a doubled over canoe is hexagonal, a geometric form associated with quartz crystals – one of the shamans’ power objects used in transcosmological travel.
A man is buried with feather headdresses, monkey fur tassels and so forth, while a woman is accompanied by her basket, mirror and other personal possessions. The grave is dug at the centre of the house for a man, and next to the family compartment for a woman.
We also see the same sub floor burials at the Neolithic Ain Ghazal in Jordan and Catalhoyuk.
At Catalhoyuk, they subdivided the floors into discrete levels, some of which were painted red. The dead were buried beneath these.
The point being here is that the revered ancestors were kept around, to be present in their everyday lives.
However, there is also some evidence – in all of these – that it is only the special, revered dead that were given this in-house treatment, and the rest could well have ended up on the town rubbish dump.
But still, I believe that all this makes it unlikely that Stonehenge, just because they buried people there, means that it was solely a royal cemetery. It is more likely that they were buried there because of what went on there – which we still haven’t figured out.