Yahya al-Haddadi accuses Uthmaan (radiyallaahu anhu) of instituting "the mother of all innovations", "opposing the Messenger" and claims a consensus on the first aadhaan being an innovation (and misguidance). All three claims are baatil (futile, false). Shaykh Muhammad bin Saalih al-Uthaymeen (rahimahullaah) said, as occurs in his explanation of aqidah al-Safaareeniyyah (p. 60):

حتى إن بعضهم قال : إن الأذان الأول للجمعة بدعة؛ لأن النبي صلى الله عليه وسلم لم يسنه، فإذا قيل له: إنه سنة الخليفة الراشد الذي أمرنا باتباعه، عثمان بن عفان رضي الله عنه، قال: وإن سنَّه إنه ليس سنة الرسول عليه الصلاة والسلام. وبهذا حكم على خليفة المسلمين الثالث وعلى المسلمين عمومًا بالضلال، لأني لا أعلم إلى ساعتنا هذه أن أحدًا من الصحابة أنكر على عثمان رضي الله عنه هذا الأذان، فيكون الصحابة مجمعين على إقرار الضلالة! ويكون الخليفة الراشد ضالاً! لأن كل بدعة ضلالة، وهذا -والعياذ بالله- غرور بالنفس وزهو، ولا شك أن من ترافع إلى هذا الحد سوف يضعه الله، وأن من تواضع لله رفعه الله، يجب أن نعرف لهؤلاء السلف حقهم ومنزلتهم عند الله، وفي العلم وفي العبادة

Until some of them said: The first adhaan for Jumu'ah is a bid'ah (innovation), because the Prophet (sallallaahu alayhi wasallam) did not institute it. Then when it is said to him, "The righteous caliph whom we have been ordered to follow instituted it, Uthmaan bin Affaan (radiallaahu anhu)" he responds, "Even if he instituted it, it is not the Sunnah of the Messenger (sallallaahu alayhi wasallam)." And through this he has judged the third khaleefah of the Muslims and upon the Muslims in general with misguidance, because I do not know until this hour of ours that anyone from the Companions showed rejection against Uthmaan (radiallaahu anhu) for this adhaan. Hence, all the Companions would have corroborated this misguidance! and the rightly-guided caliph would have been misguided! Because every innovation is misguidance, and this - and refuge is from Allaah - is from being deceived by (one's) soul and vain (arrogance). And there is no doubt that the one who raises himself to this level (of arrogance) will be put down by Allaah, and that the one who humbles himself to Allaah, Allaah will raise him. It is obligatory for us to know the status and right of those Salaf and their status with Allaah, in knowledge and in worship.