lastname-no is a nice way of identifying a person on wikitree, and I guess there is some kudos in having lastname-1. But it does have one significant flaw - because the lastname is embedded into the id if the lastname is found to be incorrect then a new id has to be created and the old one becomes a redirect.
Its become a concern of mine as I am working on the hurved ancestry line, however hurvid is often used instead of hurved and this isnt simply a transcription error official documents for many prople swap between hurved/hurvid throughout there life, and so it can be difficult to make a decision and be confident Ill not change it.
If Globally Unique Identifiers (128bit number expressed as hex) were used instead then there would be no need to change if the surname changed. There is no doubt the current name is friendlier but I just wonder if the guid concept had been explored on wikitree (its been used successfully for many years on musicbrainz.org)