Yes - so the way the HRA / ECHR works is that these are the rights individuals have, enforceable against the state. They are not enforceable against other individuals (except in very niche privacy circumstances not relevant to this thread).
This means that the HRA means that the state must not engage in torture or inhuman and degrading treatment - so a police officer must not punch you while arresting you, but if you get punched in the head in a bar brawl you can't allege that the perpetrator breached your human rights, because the puncher in the second situation is an individual not the state.
In this particular situation, the victims could quite reasonably be re-traumatised by seeing their rapist out and about in their home town. That could be a breach of Article 8 (right to private life) and potentially Article 3 (freedom from inhuman and degrading treatment).
An offender will be released on licence, which means that the non-custodial part of his sentence is in the community. This is the bit about only serving half or two thirds of a sentence in prison - on release he will still have conditions attached and if he breaches them he can be recalled to prison.
There are 'standard' licence conditions which apply to everyone, and then also conditions which are tailored to an individual, see here: www.gov.uk/government/news/licence-conditions-and-how-the-parole-board-use-them
One available condition is restriction of residence, so the parole board can order that a rapist is excluded from a particular town or area. If they failed to put that condition in, the victims could use the HRA to bring a case against the parole board asserting that the parole board's decision breached their rights under Articles 3 and 8. They would probably be entitled to legal aid.
In terms of value of the HRA to victims, victims of black cab rapist John Worboys used the HRA to argue that failures in effective police investigation amounted to a breach of their Article 3 rights: www.bailii.org/uk/cases/UKSC/2018/11.html