No it wasn’t. The issue was a custom made cake. The court ruled that the cake constituted an artistic expression (i.e. speech) on the part of the baker and they

No it wasn’t. The issue was a custom made cake. The court ruled that the cake constituted an artistic expression (i.e. speech) on the part of the baker and they couldn’t be compelled to produce speech they disagreed with. If they just wanted a premade cake there would have been no issue. Suppose at some point gay marriage is overturned, and some conservative group goes to a gay baker and commissions a cake saying "Hooray no more gay marriage! God is good!". Should they be compelled to bake that cake since they can't discriminate on the basis of religion? You might disagree with that logic, but the ruling had to do with free speech, not public accommodations. Commissioning a custom work is not a public accommodation.