NavController doc need improvement

When using IonicPage, the NavController is not up to date:
When the page return false to the ionViewCanEnter the previous page need to check the return value from the promise instead of catching the error:
this.navCtrl.push(MyPage).catch(er => {alert …}); works
this.navCtrl.push(‘MyPage’).catch(er => {alert …}); didn’t work (usage of IonicPage)
instead use:
this.navCtrl.push(‘MyPage’).then((nav: boolean) => {
if(!nav)
{ alert …}});