And yet the decision was not to ban them?
Something doesn't add up there.
The WADA Ethics Committee found against them, but the overall decision was to await further research into side effects such as altitude-sickness, sleep disturbance and a possibly adverse effect of the immune system...presumably looking at the third of the "big three" to fall into place.
Oxygen Tents fall foul of the "Potential to enhance sporting performance", and also have been judged (as above) to be "Contrary to the spirit of sport"
A health risk would have meant that the third of the criteria for the banned list would have closed the deal.
Perhaps the failure to revisit is a lack of conclusive proof of harm, and the continued inability to match all three criteria