Not at all. If you walk into a bakery and say "I want a wedding cake" they will immediately sit you down to discuss what type of custom cake you want. You would have to explicitly specify that you wanted a pre-made, off-the-shelf cake if that is what you were looking for.

It was not even a question in the lawsuit that a pre-made cake would have been an acceptable substitute.

I said "most people" because I'm sure there are people who have less formal, low-budget weddings where they grab any old cake from the grocery store. That is not what is understood when someone says "wedding cake".