Right so this is something I've actually dug into a fair bit and the situation is less "quiet scrub" and more catastrophically bad archiving practices over decades, which in some ways is almost worse.
NASA themselves admitted in 2006 that the original slow-scan telemetry tapes from the moonwalk are gone. Not hidden, not classified, genuinely lost or recorded over during the 1980s when they were reusing tapes. The footage we see now is from kinescope recordings of monitors, which is why the quality is so poor.
Now whether you find that suspicious or just depressingly bureaucratic depends on your priors I suppose.
What bugs me more than the tapes themselves is the lack of serious mainstream coverage when the admission came out. A space agency losing the original footage of the most significant event in human history and it barely registers. That does strike me as odd regardless of where you stand on the broader Apollo questions.
Anyone else been through the Goddard Space Flight Centre documentation on this? There's some interesting stuff in the NARA records if you know where to look.