A disguise and an unreliable statement are different things
The Copycat belongs to the Meddler category and is normally good. Its role text says it copies a good role in play, without the separate lying condition found on Drunkard. The dated Demo mechanics explain that a truthful disguise can have the displayed role’s functioning statements and abilities.
This is useful information even while identity remains uncertain. If two cards display the same good role, their appearances alone do not tell you which one is the real role, and they do not make both statements false.
Use duplicates to ask an identity question
Consider an illustrative pair of cards displaying Mathematician. A real Mathematician plus a normal Copycat is one possible identity arrangement. Agreement between their totals would be compatible with that arrangement, but agreement by itself would not prove it: other disguises and case effects can also matter.
The useful question is whether the displayed role is truly in play and which other identities can imitate it. Keep the real-role and Copycat positions unresolved until another clue separates them. You can use the information conditionally without pretending you have solved both identities.
Read the copied function before using it
Players in the current Demo discussion describe a Copycat using a copied Vigilante function. That is consistent with the dated disguise rules, but it is not this site’s playtest and does not establish every later interaction.
Before using any copied ability, read its target, trigger and current case conditions. Do not assume a familiar button proves a resident is the original role. The normal Copycat rule also should not be stretched into a guarantee of immunity from every possible future quirk or build change.