Would Japan's internal troubles in the 19th century have inevitably led to the collapse of the shogunate, or was the event precipitated by Japan's increasing contact with the outer world or the arrival of Commodore Perry?
Whether or not it was inevitable is impossible to argue, because we don't know how Japan would have turned out if Perry didn't arrive.
However, the major political driving force for the revolutionaries was without a doubt caused by, directly or indirectly, western contact. The actions of the sonnō jōi movement, their consequences and reactions, was what brought down the Shogunate. Sonnō jōi itself was very much a reaction to what seemed to be weak responses to westerners by the Shogunate during contacts, compared to Emperor Kōmei who was more hardlined (and who issued the edict to expel foreigners). All of which occurred due to contact with the west.
So could the Shogunate have fallen (eventually) for some other reason and the Emperor restored? Sure. Anything could happen. But what did happen was heavily due to western contacts.
To historians who have studied revolutions at-large: Is the Meiji Restoriation considered a revolution in the same vein as the French, American, Russian, etc?