Just switched a Genesis based site I’m developing from 2.0 to 2.1-r3774. I was a bit confused by the broken templates, but then realized the Genesis code had been pulled out and found and installed Jared’s BBPress Genesis extend (0.8.1) plugin which now makes everything is look good OOTB again.
https://wordpress.org/extend/plugins/bbpress-genesis-extend/
There are only a dozen dummy posts and _no_ custom templates yet so I wouldn’t really expect it to explode, but I start customizing forum templates in a few days and it seemed to make sense to start with 2.1.
Most likely you don’t have those metaboxes turned on under Screen Options.
See https://codex.wordpress.org/Administration_Screens#Screen_Options
Top Right corner of the menu’s page, click screen options, check Forums/etc then you should see them for easy addition to menus.
