Should I unsubscribe Observables lists?

To expand on @AaronSterling’s comment, I never explicitly type unsubscribe any more, after reading this article. Instead, I use the following idiom:

private _tripwire: Subject<boolean>;

ionViewWillEnter(): void {
  this._tripwire = new Subject<boolean>();
  observableFoo()
    .pipe(takeUntil(this._tripwire))
    .subscribe(foo => this.foo = foo);
  observableBar()
    .pipe(takeUntil(this._tripwire))
    .subscribe(bar => this.bar = bar);
  // repeat ad infinitum  
}

ionViewWillLeave(): void {
  // it would be nice to be able to just complete, but that won't trigger takeUntil  
  this._tripwire.next(true);
  // strictly speaking probably not necessary, but i do it in case the previous line gets to go away at some point
  this._tripwire.complete();
  this._tripwire = undefined;
}

Instead of willEnter/willLeave, these can be paired up in didLoad/willUnload or any other set of matching lifecycle events as befits your situation.