Hi Lucky_Man,
We are encouraging all users to transition to STP Phase 2 because STP Phase 1 will soon be switched off. This means that after this period, it will no longer facilitate reporting though Phase 1 and transitioning to Phase 2 ensures compliance with updated payroll reporting requirements set by the ATO. Please see this link.
At this stage, MYOB hasn't announced plans to end support for offline (local) files or applications. However, we generally recommend using online files to take advantage of enhanced features, such as automated updates and compliance tools.
Regards,
Sai