It's ADP. That's why Apple didn't reinstate ADP in the UK. The UK wants a backdoor for UK users of ADP.
And there are plenty of UK users of ADP - those who got in before it was banned still have it.
From the article:
> After the U.K. government first issued the TCN in January, Apple was forced to either create a backdoor or block its Advanced Data Protection feature
> the US claimed the U.K. withdrew the demand, but Apple did not re-enable Advanced Data Protection
> The new order provides insight into why: the U.K. was just rewriting it to only apply to British users