Dealz did a deal with toblerone makers that they would stop making twin peaks once the run was done to avoid litigation
It was all a big clever & slick marketing trick, poundland/dealz won as did toblerone/mondelez, both got free advertising, and both had boosted sales.
If they do have to stop the shape then I imagine they could make more in a different shape, which I would actually prefer it, as toblerones are a terrible shape to actually eat.
The likes of hunky dorys are sold in aldi alongside "okey dokeys" both made by the same factory. Difference here is the twin peaks are made by another company, but still, dealz will sell toberlones.