The idea doesn't impress me, and (irinically) seems still to pander to the dope Guardian reader idea that paedos can be "cured".
Firstly, it is known that some chemically or physically castrated men still go on to commit sex assaults. It's a behaviour deep in their psyche, removing the gear does'nt alway remove the desire.
A danger is that they are seen as "safe", and this is cheap for the government, and social workers can keep on playing doctors and nurses.
But they're not.
What you have done is taken someone with proven severe issues towards others. You then strike right at the heart of his sexual identity, and for paedos that is often the entire core of their personality.
Some will no doubt lapse into "acceptable" behaviour. Others will have a permanent grudge against their targets, or indeed may find a new class of victim.
This is a pattern we see with the CSA, recycling, and now criminal justice. This government doesn't "do" detail, like making things work. It has thus given up, and rather than administer processes welll, which is boring, they are going for ever higher "penalties".