Why is the nūn retained in لَنْ تَفْعَلْنَ?

Negating the Imperfect with Lan and Lam: Subjunctive, Jussive and Full Paradigms

• It is inflectional nūn
• Lan does not govern this verb
• It is a nūn of emphasis
• It is nūn al-niswah, marking feminine plural