You have to bear in mind that we still have no ancient samples from Southern Illyria, Epirus or Macedonia. Albanians largely trace their descent(autosomally speaking) from Southern Illyrians. Whilst the North and Dalmatian Illyrians were probably shifted further north and west(as todays populations).
Of course later admixtures shifted further north and east. However, this is largely anecdotal. It is ultimately irrelevant. Albanians largely possess native Illyrian West Balkan YDNA lineages. Proto-Illyrian YDNA was J2b-L283. The parent clade to V13 near Split and Bronze Age R1b in Bosnia. All 3 of these lineages are the majority in Albanians as a whole(varying region to region). Regardless of the "shift", most Albanians are directly Illyrian via paternal descent.