Earlier quoted context omitted.
The differences weren't that great. German has a number of distinctive dialects (Bavarian, Saxonian, etc.), and with Saxony in the east, there have been historical differences anyway. The Saxonian dialect has sort of become synonymous with Eastern Germany, even though it's just one of the Eastern dialects. I can think of very few differences that existed due to the separation, mainly just a few brand names that becam…
Isn't Standard German based on the Upper Saxon and Thüringian dialects anyway? I think that would mitigate a lot of the differences (e.g. the Saxons from the DDR would sound more "standard" than the Bavarians from the BRD).
So if you speak neither, both are probably unintelligible, but Bavarian also has different grammar to figure out.