Depends no? If your "100%" is based on the after value rather than the before value, you have added 100%. Though I guess there is an implicit expectation that it is the before value that is used.
This is what people normally learn in primary school about the meaning of this phrase.
It went from having 0 pattern matching to having 1 pattern matching -- that seems like '100% more of this thing we are talking about' to me. This of course only makes sense if you see '1 pattern matching' as a precisely defined abstract construct, but I guess the 100%-more joke usually requires that perspective (and is a joke precisely because it's so non-sensical to think this way).