If you can tell me what the new Java language features will be in the next 15 years, I will be more than welcome to answer you
Hibernate is already concurrent friendly on the server side as one session is completely independent and uncorrelated to other sessions wo sharing any state. We had multi processors on the server side for years and you never noticed any problem.
The more interesting challenge will comes from the future of databases. Solid state drives and maybe transactional memory might shuffle how we use databases in the future. But nobody knows really how. Once we will know, we will see how to adapt Hibernate.