What Westerners need to be taught is different from the needs of other cultures. Seekers here are seldom lacking in their discernment, but very lacking in their empathy.
I haven't experienced that the teachings need to change personally, but yes the emphasis needs to. Unfortunately westerners are being fed teachings that are more like "this meditation will make you experience a sober LSD trip" and "this one will cure your depression" and "this will give you insight into the nature of reality", because that's what westerners want. But what they actually need is teachings on compassion, loving kindness, etc, which they are in no way interested in. Ultimately you cannot have one without the other. There are no eastern spiritual paths that don't integrate both insight and compassion.
AFAIK the ads don't really correspond to the content. Regardless if you are looking for weight loss, business success, or liberation, you come into contact with the same teachings because it does all of the above. It brings people in with concepts they are familiar with.
Yeah I think you have to misrepresent to get people in, but personally I don't like that. I would rather we don't lie about it and Buddhism (for example) dies than we misrepresent it.