The statement says that it was initially recorded as a hate crime, but this will be reviewed as and when motive becomes clearer (which suggests they don't know why he did it yet), and that they have been working with various LGBTQ+ groups (best practice). I think that's a good thing.
Bristol makes far more sense now. That weekend was the last weekend of Pride, and Paul and Albert might have been planning to travel down for that. He takes parts of the bodies (the parts most likely to yield identity on investigation?) to Bristol. Probably using their tickets, so it looks like they've travelled as planned. It also explains why he didn't think he needed to wear gloves, as he'd have a good explanation why his fingerprints would be on the case as he was a lodger/other cohabitant. And wearing gloves in July would be far more memorable to a taxi driver than just another fare. So, especially if there was a good delay in finding the suitcases (wherever he initially planned to dump them), the taxi driver might never have been traced, so prints in the cab never found.
He'd then travel back to London (paying fare in cash), risking CCTV, as there was a good chance no-one would be looking, as they'd believe Paul and Albert had travelled there themselves. He could then take his time in cleaning up the flat and disposing of other body parts in London. And eventually report them missing, a few days after they failed to return as expected.
Then it all went wrong in Bristol, and his face was captured on CCTV/cyclist's GoPro.
Yes, I know that's just a heap of speculation.
And it doesn't tell us WHY he killed them, and if he doesn't tell then that might mean it remains a mystery.
I note that the police statement includes:
"We are making thorough enquiries to establish whether there may be any linked offences in the UK or overseas but so far none have been identified. Detectives will continue to build a full picture of the circumstances, including any previous incident that may be linked in any way to this case"