What if I want to change jobs while I am on an EP? -> You should ask the new employer to apply for a new Employment Pass for you. There is no need to cancel the existing EP before applying for a new one. Your application will be considered based on its merits and under prevailing guidelines.

他这里说到不需要cencel已经存在的EP 所以A公司是需要withdraw EP application吗还是，如果EP已经批准了那么B可以直接申请吧？