On gatherer is a ruling for Out of Time which says: 'If Out of Time leaves the battlefield before its enter the battlefield trigger resolves, creatures will untap, but they won’t phase out'.
Is there any rule that leads to this behaviour? Does it have something to do with the 'then...'? Or is it specfically for "Out of Time" because of the 'leaves the battlefield' condition?
It's because of the "until Out of Time leaves the battlefield" phrasing for the phasing out effect.
610.4. Some one-shot effects cause a permanent to phase out "until" a specified event occurs. A second one-shot effect is created immediately after the specified event. This second one-shot effect causes the permanent to phase in.
610.4c. If a resolving triggered ability creates the initial one-shot effect that causes the permanent to phase out, and the specified event has already occurred before that one-shot effect would occur but after that ability triggered, the permanent doesn't phase out.
Is there any rule that leads to this behaviour? Does it have something to do with the 'then...'? Or is it specfically for "Out of Time" because of the 'leaves the battlefield' condition?
610.4. Some one-shot effects cause a permanent to phase out "until" a specified event occurs. A second one-shot effect is created immediately after the specified event. This second one-shot effect causes the permanent to phase in.
610.4c. If a resolving triggered ability creates the initial one-shot effect that causes the permanent to phase out, and the specified event has already occurred before that one-shot effect would occur but after that ability triggered, the permanent doesn't phase out.