Steffen Mau (Principal Investigator at SCRIPTS and professor of macrosociology at Humboldt-Universität zu Berlin) emphasises in an interview with Lena Schneider in Tagesspiegel+ that there is not one ‘Eastern identity’. In addition, a play on this identity can be observed from various sides. Steffen Mau speaks of a reinterpretation of identity ("Identitätsumdeutung") in which right-wing actors such as the AfD are involved. 
Read the Interview here (German; Paywall).