If you needed it before (in mixed mode) you still need it
after.
You need WINS when you have a Microsoft network
using IP with more than one subnet.
(Technically you could use LMHosts but that is really
practical for most people and is a lot more trouble --
and technically you might benefit from WINS Server
with one subnet but it isn't as critical and seldom helps
much these days.)
Also note: ALL of you machines need to be WINS clients;
this includes the servers, DC, and evne the WINS server(s).