I think that is a wise decision. If it becomes necessary just point out to your users that the "quote" facility is just a way of highlighting text in a particular way. It can be used by anyone for any purpose. It certainly does not guarantee an accurate quote from an earlier post.
I suspect that you are more used to "top-posting" replies over the full text of earlier correspondence. The Nabble "quote" is more akin to inserted responses, where you are expected to quote only small snippets of an original post.
With that approach, it is expected that these will be edited to provide just enough text to put the reply in context. With such a system it is always possible to use quotes so limited that it can completely reverse the original author's meaning. Obviously, people used this approach will never assume a quote is anything other than the current author's work.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.