The Smith e-fits were not released for specific reasons known only to the PJ. I can fully understand the McCanns wanting them suppressed in view of one's similarity to Gerry, when he had credible witnesses placing him elsewhere.
I find it almost unbelieveable that in the small parish of Luz not one person appears to have been able to put an alternative name or sighting to those efits and that speaks volumes to me.
There could be a very simple reason why the e-fits weren't released earlier. As the parting of ways was less than amicable with Halligen & co., the McCanns may not have actually had them in their possession or may not have had the legal right to reproduce them. Once the Met got involved, they could have put pressure on whoever had them to cough up.
Alternatively, they were advised not to for some reason.
I can't see a reasonable explanation as to why they wouldn't have done otherwise. Withholding them due to the fact that one vaguely resembes Gerry doesn't make sense to me as the other one doesn't, and the fuller-face one resembles numerous other people, including a former PT cop, turned Maddie "expert" (not Amaral for once).