Haven't seen this mentioned on dakka at all, the new crusades sourcebook is up for preorder;
https://www.grippingbeast.co.uk/SRB22_SAGA_Age_of_Crusades_Supplement_PREORDER--product--5544.html Covers 12 factions from the Crusades East and West, Iberia and the Mongol invasion.
A and A has also been updated with the amendments as a free PDF;
http://www.studio-tomahawk.com/dl/saga2_aa_update_en.pdf Presuming that GB have updated their website taking into account the new book then some of the Crusades factions are;
Crusaders.
Saracens.
Moors.
Spaniards.
Milites Christi.
Mutatawwi'a.
Teutonic Knights.
Mongols.
Baltic pagans?