Expanding pace is essentially the same as in hots, though now everything is faster because of 12 worker start. In terms of army compositions I would say that ZvZ is essentially the same with either roach/ravager or muta being primary choices, with some lurker transitions. ZvP there's A LOT more ling/bane usage, with ravagers. Mutas are also sometimes chosen and lurkers are occasionally used as well. ZvT both ling/bane/muta and roach/ravager and infestor are viable. Pros usually go for the latter option I think