What Edward I's infamous Edict_of_Expulsion never happened, and the Jews weren't expelled from england?
Short answer : They'll be expelled by another king.
Pretty much. Nearly every western European country expelled the Jews at one time or another.
Are you sure that "centralized" is the fitting word? Especially when the most antijudaic regions were in HRE.The centralized monarchies were able to make it stick; the German and Italian states weren't, because some local ruler was always willing to take in the Jews who were expelled from his neighbor's domain.
Rather than using western/eastern divide, you should use a northern/southern one.
By exemple, while England expelled Jews in the XIII century, you had Jewish doctors being hailed in Montpellier university.
Basically, you have the policy applied in England or northern Germany appearing one century later in the south, because of many factors : Crusade in southern France carrying french customs in that matter, reinforcment of the royal power, crisis of the XIV century, etc.
Are you sure that "centralized" is the fitting word? Especially when the most antijudaic regions were in HRE.
In contrast, once the Jews were firmly expelled from England, France and the Iberian kingdoms, they didn't return for centuries.