G, the '66 Flip Top and Super Bassman are just
amp models, while
presets consist of pre-effects (if any), an amp, post effects (if any) & cab(s)(if any). They are on Droopy_TX's lists of amp models listed at the bottom of the Preset lists, as well as the list of am models in the manual. Presets 1, 2 & 3 use the Super Bassman Overdrive amp, but none of the stock presets use the '66 Flip Top. It's just there in case you want to use it.
Try copying a preset to a test location (greater than 100), then try changing the
amp that preset uses to see the Super Bassman and the Flip Top in the list.
The Acoustasonic and Acoustic Sim are new presets available for download using the Tone App.