You can see Wild Smurf but he wasn't one of the original Smurfs who disappeared back in time with them.
In "Greedy's Masterpizza," references were made to tomatoes, spaghetti, and most of all, pizza. However, tomatoes, spaghetti, and pizza are unknown to the ancient Romans and the ancient West. Tomatoes will not be known to Europeans until the 16th century when they were imported from the Americas. The process to produce spaghetti will not be known to Europe until 13th century when it was imported from China. Finally, while pizza was known to some regions of Italy for centuries, the pizzas that are depicted in this episode are of American origin introduced by Italian immigrants in the early 20th century.