No, here "get celebrated" is a passive form of the verb "to celebrate", not the adjective "celebrated".
"I celebrated my birthday yesterday."
"How did you celebrate it?"
"I celebrated it WITH a party"= I celebrated it BY HOLDING a party
---> My birthday was celebrated with a party= my birthday got celebrated with a party.
People celebrate Star Wars.
How do the celebrate it?
They celebrate it WITH a special holiday= they celebrate it by participating in a special holiday
-->star wars is/gets celebrated with a special holiday.