Are there any tenets of Sunni Islam that started out as a revolutionary idea that were resisted by the majority Sunni consensus at the time?

This Q came up as I learnt about Sheikh Mustapha Rashid’s fatwa about hijab not being compulsory going against current Sunni consensus. Since Ijma is a core Sunni principle, I wonder if there is any precedence in Sunni Islam about fringe ideas gaining eventual acceptance despite initial controversy. I already understood that Quran & Sunnah is the highest authority. What I am specifically wondering about is in matters where they are vague, thus having to resort to Ijma. I am also not looking for trivial khilaf fiqh issues such as prohibition against owning dogs or Qunut prayers, but rather on major tenets of Sunni Islam, especially those that differentiates it from other sects it deems to be outside of AhlulSunnah wa Jamaah, e.g. ahmadiyyah, baha’i, shiah. For example, i understood there are disagreements between Ibn Sina vs Imam Ghazali vs Ibn Rushd. Was any of them backed by the majority consensus at that time? Did the views of Imam Ash-Shaari and Imam Al-Maturidi begin as a fringe idea contested by most of their contemporaries? How dominant was mu’tazila among scholars during their political supremacy?