Based on this post:
[quote="Moka"]Sorry, phpBB does not have this feature. There is a MOD out there that provides this functionality:
https://www.phpbb.com/customise/db/mod/who_quoted_me/Why don't you start a poll or something to see who is interested in getting this added to the forum?[/quote]
It seems to me that Moka would be considering that if there was enough interest. That's just what I took from it though.
Personally, I think it would be a nice feature to have. Not necessary of course, but quite nice.