Learning app Duolingo has 17 million followers on TikTok, where its owl mascot plays a starring role. Duolingo is rethinking its TikTok strategy after seeing declines in organic reach.Isa Foltin/TikTok via Getty ImagesA version of this post appears in the CMO Insider newsletter.You can sign up for Business Insider's weekly marketing newsletter here.Duolingo's "unhinged" marketing …

