(*Put Important thing first: There is another method that can be used by multiple people and solve your problem, which is to create a Team Project and then create all components in Components pane to simulate a widget Library. By updating the Components (Check in & out) in the Team project to allow multiple people to use the same Components, your updates to the Components will be reflected on all component instances.
This means that you use the Components Pane and all its components in an RP file as your widget library)
I understand your requirements. If you want multiple people to use a widget library, changes to widgets or components in the widget library will not be updated to all Axure RP pages that use thses widgets or components.
The method I and you mentioned above for creating components in all RPLIB pages is also not feasible. Because all RP file page instances that use this widgets library will not be auto updated.
You need to delete all instances and auto created components used in the pages of the RP file. Then save and exit the RP file and enter again to add the widgets. The new added widgets will be new.
This seems to be because once the RP page loads widgets from the widgets library, and these widgets added have components, it will automatically create these components for the RP file. The changes you made to the original RPLIB file will not be updated to these components and its instances.
So we still look forward to Axure’s update: Once changes are made to the components in the RPLIB file, they will be updated in all RP files that use this RPLIB. This approach is more suitable for multi person collaborative projects. (This is indeed a major and important update!)
If you are solo designer for a project, you can skip using the Widget Library and directly use Components. This way, updates to all components will be reflected on all instances.
There is another method that can be used by multiple people and solve your problem, which is to create a Team Project and then create all components in Components pane to simulate a widget Library. By updating the Components (Check in & out) in the Team project to allow multiple people to use the same Components, your updates to the Components will be reflected on all component instances.
This means that you use the Components Pane and all its components in an RP file as your widget library