There will be huge layoffs because most of the senior managers' long term bonuses are directly tied to lowering costs. Doing things cheaper and better takes effort, laying people off does not. And management is nothing if not lazy. You think they will ask you how to do things cheaper, better, so some jobs will be saved? No - the deal probably assumes 15-20% cuts from total headcount to make this work, if not more. The younger folks will get an intro into what us middle agers have dealt with a long time -> NO COMPANY CARES ABOUT YOU, you are a cost to be lowered or eliminated if possible.
Regarding other banks, the constant layoffs may explain the large underground market for Xanax among BofA and WF employees. It's easier to deal with this stuff if you're numb.