ng-template – typed variable

There is no type inference for let-* variables. The let- context is part of the micro syntax parser for Angular, and an IDE can not infer the type as there is no clear origin.

https://gist.github.com/mhevery/d3530294cff2e4a1b3fe15ff75d08855

You can try to silence the IDE warning using $any()

https://angular.io/guide/template-syntax#the-any-type-cast-function

<ng-template #tileTemplate let-content>
  <h5 class="tile__type">{{$any(content).type}}</h5>
</ng-template>

You can force type inference by using a function

<ng-template #tileTemplate let-content>
  <h5 class="tile__type">{{toVideo(content).type}}</h5>
</ng-template>

public toVideo(value: any): Video { return value as Video; }