You can do both. You can be a 'Weight Watcher' in terms of being a member of a group that gives each other encouragement with the whole accountability feature (weigh-in shows whether you are still focusing on weight loss and learning from the previous week's cumulative actions). In addition, you can learn about nutrition on your own, for reinforcement of ideas you may have or ways to deal with 'problem foods.' You can use the Internet - even the WW website has good information - or do independent reading. You can ask your WW leader after the meeting for information you think you're missing.
There are tons of diets floating around the Internet - the high carb diet that uses starches comes to mind. Nothing in a WW meeting every tells you that a food (a starch, for example), is forbidden. What they do tell you is that points (basically, weighted calories) are going to be a limit you have to work with.
There are diets that tell you there are no limits you ever have to work with. They simply don't express it outright, but there is always some limit. Low-carbing give you limits. A diet that restricts you to a certain type of food on certain days is going to give you limits. They know the limits are there. Eventually, when you are plateauing on a diet, the response will be to stick to the limits or make the limits even more stringent! Hey, they are diets!
WW will tell you the same thing. If you aren't losing with X points (now called 'points plus'), they will tell you to give the level you're working with a bit more time OR if you are impatient, lower your points for a week and see what happens. Kind of basic common sense, if you ask me! WW is for support while you try to work with limits. That's all it is. It's a valuable diet for that reason - that and the fact that once you reach your goal, you can be a lifetime member and use the organization for support.
I don't see a conflict with doing WW and reading and learning about nutrition. The fact that WW doesn't spend members' time in meetings giving mini-seminars about nutritional topics is clear to me - the reason people have trouble with diets is not that they don't understand the material. They have a problem with the lifestyle! THAT'S what they talk about in WW meetings - how can you deal with x, y, and z situations when you have a solid ingrained habit of sabotaging your weight.