I see your point.

A removal mechanism is not (yet) implemented. But in principle, we could adjust the instructions in Update.md so that it does a minor "refactor" of the filesystem each day, then newer abstractions can form, while irrelevant gets pruned/edited. That's the beauty of the architecture, you define how the update can occur!

But if you do have a new memory (possibly contradicting an old one), is it really a good idea to prune/edit it?

If you are genuinely uncertain between choice A and B, then having them both exist in the memory archive might be a feature. The agent gets the possibility of seeing contradictory evidence on different dates, which communicates indecisiveness.