So who's decision was it not to release them
Current evidence appears to point to the McCanns - Kate even avoided mentioning these efits in her book, in the section on efits.
And, considering they're the ones who commissioned the investigation that produced the efits and were therefore the ones you'd expect to release them, you really have to ask why
Yes, I know, you will say "but the PJ had them!" Maybe they did, but they didn't have them first. The McCanns and their PR team really have no trouble criticising the PJ for its alleged laxity, so it's surprising that they didn't move to release the efits themselves when they saw the PJ wasn't bothering.
Of course, they may have been concerned about releasing an efit of man with facial features not too disimilar from Gerry's, who the eye witness in fact felt was Gerry, carrying a small child in the direction of the beach, where some "[ censored word]" had suggested a dead Maddie may have been buried, at a time when the only people who could 100% corroborate that Gerry was actually somewhere else were his friends from the Tapas group. It was far easier for them to hope that "everyone" would believe Tannerman was the culprit, as that had no complications for them.
Now, I should point out that I don't necessarily believe that's what happened on the night Madeleine disappeared, but I do think this is an example of the McCanns interfering with the investigations and creating more of a problem for the efforts to find Madeleine.
But, I don't really know davel. Who do you think is responsible for not releasing them?