It’s correct that the Lancet study, by far the most authoritative available, deliberately excluded Fallujah, because that would have raised the estimates much higher — recall that as in all scientific inquiries in related areas (technically, anywhere), this one is based on extrapolation from samples, and they wanted to err on the side of conservatism. For the same reason, they included Kurdish regions where there was very little conflict, thereby reducing the estimates.
You are also correct that the study ended before the devastating attack on Fallujah, a major war crime. For this and many other reasons, their 100,000 “most probable” estimate would be considerably higher if a similar study were done today.
Judging by news reports (not in the US, as far as I saw), a later study of a Swiss research institute basically confirmed the Lancet study, in their case investigating only direct killings.
The Iraq Body Count studies have been useful, but as the investigators explain, these are considerable underestimates, relying solely on newspaper reports of deaths and official figures. The Lancet study was a much more serious inquiry, and therefore has been ignored or attacked regularly in the US (and to a less extreme extent, England).
Any mention of it is usually accompanied by the statement that the “controversial” Lancet report estimates that extra deaths resulting from the invasion “may have been as high as 100,000,” or something similar. Every such study — e.g., the effects of cancer surgery on longevity — is “controversial.” And the 98,000 estimate was “most probable, so that an honest report would add “may have been as low as 100,000.
What is amazing about these studies is that they have been undertaken.
In the past, atrocities carried out by the US and its clients rarely are investigated. Take Vietnam. Apart from completely fraudulent “body counts,” there was essentially no inquiry. We do not know, literally within millions, how many people died as the result of the US attacks on Indochina. Same in case after case. Crimes of enemies have to be scrupulously investigated, with massive forensic inquiries, etc. One’s own have to no less scrupulously ignored (or simply denied).