My understanding is they've done bugger all. MP's behind the bill have merely said they won't use the provision, primarily because there is no sufficient technical means to do so, but the wording of the bill hasn't changed.
If the bill goes through as is then businesses may be compelled to create the means to do so, regardless of it breaking encryption - maybe they won't do it right away, but they'll have the perogative under law. It wouldn't be too much more effort to throw in a gag order and prevent public disclosure. I'm sure Signal and a few others would kick up a stink and leave if they were targeted, but I could see Facebook and Google signing up, for a price. Hell I'd be more surprised if WhatsApp didn't already have backdoors.