The Imam must have defined it somewhere. Otherwise the above will not be clear enough. Two different meanings of bidah can be read into what was quoted. Bidah with the meaning that something which has no basis in the shariah and the other meaning being bidah as something which is simply new.
If you go by the latter meaning, then it would be as what you say. But if you go by the first meaning, then things like mawlid etc won't fall under it, because they have a basis in the shariah and only its form is new which is no different to preaching, which has a basis despite there being innovated forms of preaching. By this meaning then what it would mean is that he is opposed to any bidah which has no basis in the shariah and that he does not consider any bidah w/o a basis in the shariah could be classified as good or bad. Meaning he considers a bidah w/o basis as always bad.
So to know what the Imam meant precisely, we would have to know how that Imam defined bidah.