In order to add labels to Wikidata entities in Arabic dialects using QuickStatements, we have to let them supported by Mediawiki: North Levantine Arabic (apc), South Levantine Arabic (ajp), Gulf Arabic (afb), Hejazi Arabic (acw), Najdi Arabic (ars), Hadhrami Arabic (ayh), Sanaani Arabic (ayn), Ta'izzi-Adeni Arabic (acq), Mesopotamian Arabic (acm), Cypriot Arabic (acy), Egyptian Arabic (arz), Northwest Arabian Arabic (avl), Sudanese Arabic (apd), Bahrani Arabic (abv), Libyan Arabic (ayl), Tunisian Arabic (aeb-arab), Algerian Arabic (arq), Moroccan Arabic (ary), Hassaniya Arabic (mea), Saharan Arabic (aao), and
* North Levantine Arabic (apc),
* South Levantine Arabic (ajp),
* Gulf Arabic (afb),
* Hejazi Arabic (acw),
* Najdi Arabic (ars),
* Hadhrami Arabic (ayh),
* Sanaani Arabic (ayn),
* Ta'izzi-Adeni Arabic (acq),
* Mesopotamian Arabic (acm),
* Cypriot Arabic (acy),
* Egyptian Arabic (arz),
* Northwest Arabian Arabic (avl),
* Sudanese Arabic (apd),
* Bahrani Arabic (abv),
* Libyan Arabic (ayl),
* Tunisian Arabic (aeb-arab),
* Algerian Arabic (arq),
* Moroccan Arabic (ary),
* Hassaniya Arabic (mea),
* Saharan Arabic (aao),
* Chadian Arabic (shu).
Please let them supported by Mediawiki and if you like to have the native names of these dialects, I can give them to you.