If you look closely
you can see one here, at 0:17 by the broken AC unit or whatever it is that's sparking (Good replacement for an electric barrier, BTW! I wonder if they intend to place more environmental hazards like that).
Seems the side of the portal bird's flight pattern is facing Abe rather than the screen now, and I wonder if that's a mistake or if there's a reason for it.
But I will agree that the blue-white cloud is a little naff and underwhelming... To 3D-ify and emulate the old effect, I'd try having a sphere that doubles as the portal opens, one floating up, another floating down, and a narrow, sparking column of light stretching out between them. Mudokons would jump into said column, and maybe it could widen briefly as if "consuming" them when they jump through it. Or maybe the disappearing models could be masked by a bright white flash or something if you wanna be lazy about it.
But perhaps it's too hard to do for little payoff/fan satisfaction when there are other more important areas of the game to work on.