The current release cycle is pretty fast.
Jira 8 should arrive in the next 6-12 months.
I’m wondering what could be expected?
Is Atlassian planning to improve security and performance over functionality ( leave it to the apps vendors) or maybe some major changes have been already planned?
Should we (vendors) be afraid?
I’m only guessing, but I’m personally running under the assumption that the new UI from cloud will be the big ticket item in Jira 8.
See Let's talk about Jira 8.0 to get a better idea what to expect in Jira 8.0. Preparing for Jira 8.0 | Atlassian Support | Atlassian Documentation specifically clarifies what changes vendors should be aware of.
Hope that helps.