what you mean? synthesisers are software... I think the context is clear here and we're talking about software made for music, so the usage of patch is accurate. If author wanted to use "patch" to mean patching a file they would likely be specific or context could be inferred.
"A patch is data for modifying an existing software resource such as a program or a file"
Which is what patching synths/drum machines (and files) does.
I am close to releasing an iOS Camera app (yes another one lol) called Invisible Camera. It's a minimal app that works the way I like to shoot with my Fujifilm camera: focus on what I see, quickly apply a look / filter with a slider and shoot. The processing pipeline reduces the default color science applied by iOS to result in a more pleasant look.
"A patch is data for modifying an existing software resource such as a program or a file"
Which is what patching synths/drum machines (and files) does.