The adapt intent service doesn't remove the registered vocabularies when a skill is unloaded, it unloads the intent itself but neither regexes or keywords are removed. Meaning if a skill has a vocab file

test.voc

stew
meatballs

and it is changed to

stew
carrots

meatballs will still be a match. The same goes for regexes.

The intents themselves are removed correctly so if an intent is removed completely it won't match any longer but as long as an intent is reused all previous registered vocabs will be available.

Not sure if this is a core issue or an adapt issue, since adapt doesn't implement the detach code.