We have two 10 l. MSR Dromedary bags of considerable vintage. Maybe we may have less sensitive palates but the reported phenolic flavour of has not been something that we have noticed . I do not know whether this has to do with changes in MSR specs over time or the fact that as a trip preparation routine we flush the Dromedaries with a weak bleach solution then rinse before filling with tap water. We do use Pristine water treatment for any water we collect from streams so perhaps there is some incidental benefit in that to suppressing any phenol taste.
Nancy, I remain interested in your ongoing investigation.