Yea, I don't want to get rid of them yet because people could revive them (in theory...)
Tags are disabled, but the tag system doesn't allow for mass tag removal within the php interface. This means the tags are still in the tag cloud.
I've put the question up to the tag system developers
here
If it's possible it will be done.
If not, then the recycle threads will all just be purged.
Chances are people won't bother reviving them so they'll be purged anyway.
Still, want to get rid of the tag cloud litter...