What proof do you have? On what planet would major banks piss off the most capricious and unrestrained president in modern US history? What possible upside could there be for them? Trump (34 time fraud felon known for scamming everyone he can and using his position in government to massively enrich himself) was almost certainly "debanked" because he is doing more of the same shady shit that he's known for and the banks are obligated by the law to treat him like anyone else.