Ziggy routes in HandleInertiaRequests

I am playing around with the new Breeze+Inertia+Vue setup and noticed the routes for ziggyjs are now included in the share method of HandleInertiaRequests. I wonder why this is?

At first I thought, this wil refresh ziggy's routes on every navigation. However, it seems these routes aren't used...

To check this, I added an unknown route to Dashboard.vue:

{{ route().has('this-is-a-new-route') }}

Then build the project (to prevent the page from automatically being reloaded). Without refreshing the app I added the new route and navigated to the dashboard. Here it says "false" (route is unknown to ziggy) until you hit refresh.