You can see for yourself how ludicrous that claim is if you simply visualize a map of Germany after the Second World War.
Then the Polish corridor was not just expanded, but East Prussia itself was eliminated.
And just to be certain, all Germans were driven out of Eastern Europe.
So, was that a casus belli?
No, for at least two reasons: 1) Everyone, including Germans themselves, understood that was just punishment, indeed mild considering the monstrous crimes committed by German leadership.
And 2) the border changes and relocations were enforced by overwhelming military power of the victorious Allies.
So, again, the problem with Versailles is not that it was too harsh, but rather that first, Germans did not feeeeeeel defeated, and second, the terms were not enforced by visible military power.
Indeed, just the opposite, the Allies soon abandoned such efforts.
Bringing this discussion up to date, the "lessons of Versailles" are the same lessons we've learned again in Iraq & Afghanistan: peace treaties not enforced by adequate military power are not worth the paper they're printed on.
All are products of Democrat administrations, Wilson & Obama.
Had West Germany not been powerless following WWII, it could have been a casus belli. There was plenty of irredentist sentiment in Germany clear into the 1970's. West Germany's official name for East Germany was the Soviet Zone of Occupation--they didn't consider it a real country--and for a time, West Germany threatened to sever diplomatic relations with any country that recognized East Germany.
West Germany also laid claim to the territories east of the Oder River seized by Poland and the Soviet Union. Any official West German map published before 1972 portrayed Germany with its 1937 borders. The government of Willi Brandt had to overcome considerable oppostion to enact the treaties in which West Germany finally accepted the post-WWII border.