Sending players on loan to clubs barely surviving relegation with a novice manager is a recipe for disaster IMO.
There's a very good chance they start badly, Rooney is sacked and the new guy doesn't like Delap for whatever reason.
That's assuming they're even still in the Championship at that point.
Not to mention it's a bit of a step backwards to end up back there 2 years after leaving, and judging by his performance against Derby and the 4 match ban for violent conduct that followed, not a lot of love lost there.
If you're after a Championship loan, IMO all the best ones I can think of come from players going to clubs who finished around the promotion spots who are trying to make another push. Mason Mount at Derby 2019, Tammy Abraham at Villa in 2018, Harrison at Leeds last season, Tosin at Blackburn etc.