I work at incident.io and we’ve had to help a number of our customers who were affected by this. While Atlassian frame it like you can migrate, there’s no official migration story and the feature lists don’t match at all.

We’ve got a good migration story (import OG schedules and escalation paths, etc) so most customers just migrate to us, but if you didn’t have that option the Atlassian migration is much more painful.