For context, see https://security.meta.stackexchange.com/a/1208/836.
In essence:
"This question is protected to prevent "thanks!", "me too!", or spam answers by new users. To answer it, you must have earned at least 10 reputation (not including the association bonus) on this site."
Suggested addition to existing message is in bold.
I think it's a good idea - to me, it isn't immediately clear that you must earn the reputation exclusively through other people's votes on that site, given the original description alone (I can see that I have that much reputation - how is it not on this site?). I assume the reputation link goes to the general FAQ on reputation, which also doesn't address this particularity.
As an added bonus, it also introduces newer users to the association bonus (I didn't know that happened until it actually did, although that was a nice surprise).
That said, your suggested rewording made more sense before the edit. It should be something like:
You must have earned at least 10 reputation on this site (without an association bonus).
The link should still be there, but you must earn 10 reputation without the association bonus.
I think that just having "on this site" alone is not enough.
When a user looks at their rep on the top right hand corner, there is no distinction between bonus rep and site rep. In the mind of the user, that number is their rep for this site, since they are oblivious to how SE internally counts rep.
This is reinforced because on the privilidges up to 100 are ticked when you get 100 bonus rep:
Notice that the "remove new user restrictions" explicitly mentions that now protected questions can be answered.
This has been implemented meanwhile; the current notice reads
🔥 Highly active question. Earn 10 reputation (not counting the association bonus) in order to answer this question. The reputation requirement helps protect this question from spam and non-answer activity.
