IMO it really depends on the rest of your party.
If it's you and a spouse and the 2 year old, and if you and your spouse dislike splitting up for rides or parts of the day, then no, leave it until later. If it's just the 3 of you and you guys don't mind splitting off and doing different things, and if the adults really want to go to Universal, then sure, go.
If it's a varied group and most people in the group will get a lot out of the parks, then the enjoyment that the 2 year old can get will be fine, IMO.
they are pretty, fun, vibrant places, and there ARE play areas to spend some time in (the ball play pit back behind the Curious George waterplay area (follow the footprints to keep from getting soaked while getting back to the ball area!) is great fun. Super-soft balls to play with and shoot out of cannons and suck up with "vacuum cleaners"...loads of fun. And, again, they are supersoft and while they might startle a small one, they don't *hurt* if you're hit with one.