Containers would still be a thing, but its implementation would be much easier. What jails (a.k.a. containers) actually do is try to build a fence around a proc

Containers would still be a thing, but its implementation would be much easier. What jails (a.k.a. containers) actually do is try to build a fence around a process so it looks as if its isolated. With a microkernel, this process would be much easier since every component of the kernel is already isolated. The actual kernel would remain the same and wouldnt need any fences (it just routes between components), and the container would just launch new instances of the kernel modules it would need.