Novels always have the deleted scenes in them. Fans always uses the novels to back up claims they make. The script that is online is the final script, the one that was used for filming. So ya, those do mean something. But obviously the biggest piece of evidence is the film itself, which we have already pointed out.
Plus, if the egg chamber was really a different room, than how did Lex and Scar find their way out of the pyramid so damn quick? The sacrificial chamber was very close to the entrance, hence why they were able to find their way out.