Companies like EvoNet can resell the services of other ISPs who have IECS/IECNS licences because their upstream provider has the correct licences. They just act as a reseller. I suspect that's how they're keeping other fibre users online by converting those accounts into accounts that have access services resold by them, and internet connectivity for DSL customers is done through a provider like Internet Solutions, also by reselling accounts.
So I wouldn't expect you to lose connectivity, but I do expect Evonet to start addressing their financial situation in 2019.