I think this serves as a reminder to close-voters that we're not supposed to close a question as a duplicate, unless the master question addresses exactly what was asked. The master question may address other elements not present in the dupe, or a brief comment may be necessary to explain to the OP how the master question answers theirs. But a question that's just pretty close should not be a duplicate target.
Close voting becomes almost mechanical when you do it enough, and it some ways that's bad. Close voters are often too hasty to close questions as duplicates. The term exact reminds us to be cautious. It reminds us that "they could figure it out from this question" is not sufficient reason to dupe it to "this question."
It reminds us of this, and in doing so makes us better close voters and close reviewers, at the expense of confusion to novices.
I wouldn't recommend simply removing "exact" from the phrasing. We can explain what it means to novices. And sometimes when they say "but it's not exactly the same," they do actually have a good reason why it shouldn't be duped! In contrast, they cannot fix our mistakes nearly as easily. Not being familiar with the site, they may not know how or be able to flag or post on meta. (Flagging one's own posts is allowed at 1 rep, but only if you have a verified email address. Otherwise, 15 rep. And posting on meta requires 5 rep. And they have to know how to do it.)
While I think the trade-off is worthwhile, that doesn't mean I think this is the best way to do it. We're not really limited to just two possible phrasings (the current one, and the same phrasing except with "exact" dropped). There's probably a better way of phrasing it that simultaneously:
- is clear to novices, and
- has the effect of reminding close voters not to vote to close based on mere similarity or the possibility that the OP will figure out the answer.