Yes, it is true. DovBear notes the stunning similarity between the Greek banquet known as a symposium and the Passover Seder. Few Jews realize the Seder is a rabbinic invention. The rabbis instituted the seder to standardize practice after the destruction of the Temple. The Haggadah is an outgrowth of that standardization. And the Seder mirrors a Greek Symposium in many ways. It also explains the term afikoman, as DovBear notes:
The Greek word epikomon means "after meal entertainment" and likely (again per Wikipedia) refers to the "games, songs, flute-girls, slaves performing various acts, and hired entertainments" that followed the discussion and the food. When the Sages said "one may not add an afikoman after the paschal lamb” they were referring to (and outlawing) this practice.
And also this:
We close each segment of the seder with a cup of wine. At the symposia the same custom was followed.
* Greeks and Romans both started their banquets with vegetables dipped in salt water, and charoset was a common dish (as implied in Pesachim 2:8 where it's suggested that charoset was served year round with flour)
In other words, the rabbis took a common secular practice, widely popular in the Hellenized world, and cleaned it up a bit, removing the raunch and using the order to tell the story of Passover. (DovBear notes NCSY does this borrowing from secular culture all the time.)
Conservative scholar David Golonkin has an excellent article (also linked by DovBear) on the origins of the Passover Seder with much more information. Read it, if you have time, before the big event.
Another opinion on Afikomon here.
The custom of not eating gebrockts (wet matzah) deconstructed here.
Kitniyot deconstructed here.
Marijuana as kitniyot here.
BTA posted on the so-called Kuzari Proof here.
I see that Jewish Atheist has a post on the Succot incident here.