Possible. Been a PR war from the start. SY could be playing their own little game. Though imo it largely just looks like they are being extremely quiet for the corporation of the Portuguese.
Scotland Yard don't play PR War Games with Cases in foreign countries. Few that there are. If there had been anything to hide then they would never have become involved in the first place. There is no Law that said they had to. in fact, I have wondered why they did.
And then I look at the complete cock up of The PJ by a man who was about to become an Arguido in the Case of another missing girl child, of which was used by The Portuguese Media, to facilitate a horrendously unsafe conviction. And then I know for why.
Madeleine McCann is a British Citizen.
And besides all of that, The British Government have never quite forgiven themselves for how badly they let down Michael Cook. This could not be allowed to happen again, without a vestige of evidence.