Ion-tabs - should it load all the tabs html?

Just by chance I was looking at the html within Chrome on a sub page from ion-tabs

in app.module.ts - IonicModule.forRoot(MyApp, {tabsHideOnSubPages: true})

To my surprise the html contained not just the html from that page but also the html defined in each ion-tab.

Is this the way it is designed to work?
… and if so is it not putting more resources in the DOM than is required making page loading slower?