Valeyard I would never include an "update all" command in official update instructions, for a few reasons:
- More difficulty troubleshooting if an issue pops up after an update
- Unexpected changes for the user if they have not read the changelog of the other extensions
- Additional steps could have been suggested in the changelog of other extensions, like running migrations, executing a command or setting up new permissions
Forum owners are of course free to manage updates in any way they prefer, but blindly updating extensions via Composer can be dangerous because Composer itself has no mechanism to help with required or suggested pre- or post- update steps.
EDIT: as for the difference between require and update, in the context or a Flarum extension, require will actually update the requirement in composer.json if it isn't already *, while update will only constrain the version further down using the provided version. So while require vendor/package and require vendor/package:"*" save the version requirement differently, update vendor/package and update vendor/package:"*" have the exact same effect, making :"*" redundant.
