Once I upgrade to Ionic 2 Beta 7, I notice that the generate command is missing from the CLI. Did I miss a change reported on the generator? It was there in Beta 6.
First of all beta.6 and beta.7 are releases of the Ionic Framework which is used for building apps and I guess that you’re referring to the Ionic CLI which is used for running commands such as ionic serve, ionic generate, etc… Looking at the Ionic CLI Changelog it seems that there were some changes related to the generate command. I would suggest you to update the Ionic CLI to the latest version (using this command):
npm install -g ionic@beta
For some reason when I did npm install -g ionic@beta earlier, I was only getting .26, but I just retried and got .29, which does have the generate command. Not sure what happened, but I am going to assume it was my fauilt. 
thanks!