I don't know if this is already the case, but I think the Bitcoin developers should code the changes to be made in case an algorithm used by Bitcoin becomes obsolete. I'm thinking in particular of SHA-256, what would happen if tomorrow this algorithm became completely obsolete? Shouldn't there be an alternative solution before that happens? I'm not necessarily talking about including this "new replacement code" in the Bitcoin code, but at least having the code on hand, ready to replace the current code. What do you think?