They do not want to work with him again. We know this because Deutsche Bank very publicly cut all ties with him in 2021, after individual divisions of the bank cut ties years earlier. Banning Trump ≠ they want to work with him again, obviously. Trump's team cherry picked a bank employee here, an accounting professor there, paid them hundreds of thousands to lie an make an ass of themselves, for a Hail Mary attempt. It didn't work.
As was pointed out in the trial, this is false. Trump did what he did in order to pay less; that is, if he were honest about his financial condition, he would have had to pay more in interest to the banks. The banks also only have so much money to loan out. Trump was dishonestly taking hundreds of millions, which could have prevented honest businesspeople from receiving access to funds they needed.
Trump also refused to pay Deutsche Bank in the past. He even had the balls to sue them when he couldn't pay! He said they caused they Great Recession, which hurt real estate, so it was their fault he couldn't pay. Then he got one division of Deutsche Bank to loan him more money to pay back the other division of Deutsche Bank he still owed money too. It was extremely shady, and many of the bankers involved met mysterious deaths, hanging themselves with dog leashes, etc. It's an interesting saga, but chuds are too busy staring at Hunter's dick pics, so whatever.