For some shlokas and Pasurams, the Phala-shruti says that “there is no rebirth” or “one will reach Sri Vaikuntha.” However, in our tradition, it is said that Sharanagati is the only means (Upaya) to liberation (Moksha). If so, how should we understand these benefits mentioned in the verses?

The meaning behind saying that the Phala-shruti of certain Stotras or Prabandhams grants Moksha is this: by reciting those pasurams or verses, we will certainly gain a connection with a Sada-acharya. Through that teacher, we will eventually perform Sharanagati and thereby attain Moksha. The idea is that it leads us to liberation step-by-step.