Good morning Kristiina and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
I would love to help you with this topic.
After one year, when your licenses expires, the plugins will still work if you do not choose to renew.
But, you will need to “freeze” your the Events Calendar related plugins to their current version (all of them) to ensure they continue working properly.
You will also lose premium support access
Let me know if that helps.
Have a great day!
Geoff B.