I reserved the same excursion. Do you mean that they will not bring you back to the ship with a bus?
The excursion text tells this about the trip:
Upon arrival, board a motor coach for a scenic transfer to the island's capital, where whitewashed buildings and cobblestone streets beckon exploration.
Wander through the narrow alleys adorned with bougainvillea, browse boutique shops offering handmade crafts and souvenirs, and immerse yourself in the laid-back ambiance of this iconic Greek destination.
Enjoy the freedom to design your own itinerary, whether it involves savoring a traditional Greek coffee at a quaint cafe, sampling local delicacies at a charming taverna, or simply soaking in the breathtaking views of the Aegean Sea.
Escape the hustle and bustle of the town's rush hours and embrace the leisurely pace of Santorini life, knowing that your comfortable ride back to the port awaits, allowing you to depart at your convenience.