What Multiplayer Architecture to chose in 2019

I'll try to make this short and to the point.
I did a multiplayer card game project back in 2017 using unity + photon. The entire thing was done mostly via RPC calls . [PunRPC]
Now I am thinking of doing another online multiplayer project just for practice. I there are words everywhere that unity is ditching it's Unet and adapting something new.
So which Architecture should I chose that will keep my skill relevant when the new Multiplayer API hits market?

PUN / Unet / PhotonBolt / PUN2 / Socket.io(have no Idea what that is) / Mirror / Something Else...

Thanks in advance.

Edit : Free API/Assets are preferable.

 

*scratches chin*

I guess you won't be choosing SpatialOS.

 

I think as of now it worth to hold off that decision a little bit (1-2 weeks I think, if you can afford it).

 

Write an abstraction layer that sits between your gameplay code and the underlying network library.