If you talk to anyone who studied at a Qur'ānic school before independence, you'll find they learned their letters by reciting a little ditty in Darja that goes ألف ما ينقط شي، البا نقطة من تحت، التا زوج من فوق... etc. (Alif ma yənqəṭ ši, əlba nŭqṭa mən təħt, ətta zuj mən fuq..., ie: "Alif is not dotted, ba has a dot underneath, ta has two on top...") The same ditty existed in Kabyle: alif u yneqqeḍ ara, ba yiweṯ s wadda, ta snaṯ ufella... . My own aunt learned her letters that way before independence - in a school affiliated with the Association of Muslim Ulama, who today are pressing for a school boycott if dialect is officially introduced as a means of primary instruction... Well, it turns out that this exact ditty is already attested in Franciscus de Dombay's Grammatica linguae mauro-arabicae, a study of the Arabic dialect of northern Morocco published in Vienna in 1800, thirty years before the occupation of Algiers, when European power in North Africa was limited to a handful of ports:
Standard Arabic was, of course, by far the most important language to learn. But it turns out that at least one other language was taught using Darja: Kabyle Berber! In Des noms et des lieux, Mostefa Lacheraf notes:
A propos de ces départs pour les zaouias du Djurdjura [...] je découvris l'existence de poèmes mnémotechniques que ces jeunes gens arabophones des Hauts-Plateaux et du Tell apprenaient par coeur dans le but de se familiariser avec un vocabulaire kabyle fonctionnel, et pédagogiquement bien choisi, qui serait susceptible de les aider à se reconnaître dans leur nouveau milieu. Je regrette de n'en avoir pas gardé un spécimen, mais je me souviens que dans cette poésie pratique, utilitaire, au rhythme bien élevé, en un dialectal correct, figuraient des verbes, substantifs et expressions berbères avec leurs équivalents arabes désignant des objets et des actes essentiels à leur vie courante. (pp. 218-219)
[Through these trips to the zawiyas of the Djurdjura... I discovered the existence of mnemonic poems which these young Arabic speakers of the High Plateau and the Tell learned by heart in order to make themselves familiar with a practical Kabyle vocabulary, pedagogically well chosen, which would help them to find their footing in their new situation. I regret not having kept a specimen, but I remember that this practical, utilitarian poetry, with a good rhythm and in a correct dialectal [Arabic], included Berber verbs, nouns and expressions with their Arabic equivalents, referring to objects and acts essential to their daily life.]
I've written previously about a Classical Arabic poem intended to teach Songhay in a similar context: students coming to study in areas where a different language is spoken. Unfortunately the poems Lacheraf describes have not been published, as far as I know, but the papers of the noted anti-colonial leader Shaykh Aheddad include a Dardja-Kabyle wordlist presumably intended for the same purpose; this is described in Aïssani's 2012 article Le lexique manuscrit Arabe dialectal-Kabyle de la Zawiyya historique de Cheikh Aheddad.
The merits of teaching in Darja are open to debate, as are the motivations of Benghabrit. But to go into a sudden moral panic over Benghabrit's proposal, you need to ignore not only current but also historical practice among Algerian teachers. Anyone who really thinks Darja should be banned from the classroom should push to have that actually happen, not wait until someone admits to it to start protesting - and should acknowledge that doing that would in fact be something new.