There was also a comment on the video that mentioned that the fix probably wouldn't last. The battery packs are a unit and they don't like it when pieces are o

There was also a comment on the video that mentioned that the fix probably wouldn't last. The battery packs are a unit and they don't like it when pieces are older / newer than the rest of the unit. Tesla might know that while replacing a single cell would fix the immediate problem it would eventually cause the whole battery to shut down. Maybe this is similar to when you have something really bad happen to an ICE motor (ie. broken valve), but you drain and flush the engine oil, which "fixes" the problem. And then 6 months later the engine grenades requiring a full replacement.