MSP430FR2355: basic isr question.....break statement?

Given that you have to enable interrupts what is the value of the break statement in the UCRXIFG and UCTXIFG below?  Doesn't it stand to reason that if I did NOT have the break in the UCRXIFG and did NOT have the UCTXIE enabled that I would still return at the end of the case of UCRXIFG?  I understand that in a normal case statement that you would go through all the cases if you didn't use a break statement but given that enables are used here it seems that breaks are unnecessary??

#pragma vector=USCI_A1_VECTOR  //radio communication
__interrupt void RF_ISR_USCIA1(void)
{
    switch(__even_in_range(UCA1IV, USCI_UART_UCTXIFG))
    {
      case USCI_NONE: break;
      case USCI_UART_UCRXIFG:
          *rxMssg = UCA1RXBUF;
          rxMssg++;
          rxCount++;
          LPM3_EXIT;
          break;
      case USCI_UART_UCTXIFG:
          LPM3_EXIT;
          break;
      default: break;
    }
}