Now that we are at the stage where the HO is not openly funding OG, I fancy there will be no more funding announcements and OG will just fade into the background - officially still open, but little more than a liaison unit with Portugal.
The case will be actively investigated for as long as there is something to be investigated; which appears to be the situation as far as Madeleine's case is concerned.
If or when that situation changes and all active lines if inquiry are exhausted I believe we will know about it ... as has happened in Claudia Lawrence's case for example.
Claudia Lawrence enquiry moves to reactive phaseAssistant Chief Constable Paul Kennedy, who attended the family meeting, said: “Step by step, we have explained to Claudia’s family the extensive work the review team has conducted in an attempt to determine precisely what happened to Claudia.
“The team has reviewed the entirety of the initial investigation into Claudia’s disappearance in 2009, and as a result, has identified many new lines of enquiry which have been pursued with vigour and determination.
“Despite their exhaustive efforts, the support of national experts, the application of the very latest forensic techniques to exhibits recovered many years ago, and despite the team tracing and speaking to many people who did not come forward in the first enquiry, we have sadly not been able to find that crucial piece of information.
https://northyorkshire.police.uk/news/claudia-lawrence-investigation/claudia-lawrence-enquiry-moves-reactive-phase/