JBDS-2734 states the following:

• The availability of the wizards is depending on the initial selection when hitting the above key combo.
  => with nothing selected there are wizards for managing connection profiles and Forge addons and for creating new projects.
  => with e.g. a project selected there will be wizards for setting up support for JPA, JSF, and so on as well as for creating classes, generating entities, scaffolding a user interface, etc.

After starting forge2, I navigate to my project

[workspace]$ cd my-mobile-app
[my-mobile-app]$

Tab (eventually) provides a list of forge2 possible commands, of which jpa-new-entity is one.

Ctrl+4 opens the forge2 wizards list window but only the wizards for connections, addons and new project are displayed.

Navigating down to scr/com/company/example/mymobileapp/model again only shows the wizards for connections, addons and new project.