I don't know what the personal reasons are; but it seems a bit like the Keith Barker situation where he had personal reasons for wanting to move to the South Coast.

Not nice to speculate but a personal issue will generally involve the relations. Let's hope he'll find he's happy at Warwicks as he sure won't let anyone down.
Maybe I'm reading too much into the signing but one thing it does suggest to me is Warwickshire are confident the championship will not be reduced any time soon. We wouldn't be making such a signing for a measly ten game championship really now would we?

On BBC north east Rushworth spoke recently quite firmly against the Strauss review. Think I posted the link here a fortnight ago.

Bizarre signing and what's even more bizarre is awarding a 36 year old a two year contract. Having said that, I hope he does well and takes loads of wickets for the Bears

I think the batting needs recruitment....

I'd say more out of the blue rather than bizarre. One of the countries leading championship wicket takers signing for a Div 1 county which has had issues in it's bowling for the last 4-5 seasons. Even when we won the title in 2021 the bowling looked powder puff in the first 10 matches. Next to getting Keith Barker back I can't think of a better signing. It saves us having to take a punt on an unproven Aussie Sheffield Shield stock bowler like we went for this season. Overseas options for next season now - top order or spinner the priority?

I also think this is a good signing. He’s experienced, proven at the level and doesn’t seem to have a track record of injury, all things we’ve been crying out for.

As mad says, he is definitely not in favour of the Strauss review recommendations. He was a guest on the County Cricket Natters podcast on 25th September and spoke about it a bit on that (there was also a mention of yours truly and this forum in the discussion of our match against Gloucestershire).

The discussion starts about 29 minutes in:

https://podcasts.apple.com/us/podcast/county-cricket-natters/id1552562603?i=1000580557268

Overall, Chris Rushworth comes over really well on the podcast, though you wouldn't guess that he was about to leave Durham. He actually says that he not only is not in favour of the reduction from 14 games but he wasn't happy when the Championship went down from 16 to 14 games.
He is (or rather was) the Durham PCA rep, which says something about how highly he was respected by his teammates.

Chris Rushworth got his county cap before the start of play today - well deserved, i would say.

He's now signed a contract extension:
https://edgbaston.com/news/rushworth-agrees-contract-extension-until-2025/