If Pakistan so such things again definitely ICC will ban the Pakistan team from the International format. So they need to take strong steps because Sri Lanka is not the worst team, which they have their own good and negative side of batting compared to Pakistan.
The Pakistan cricket board has nothing to do with the security of the other team, the security must be provided my the authorities because there is already a treat and the government should take measures to make sure everything is safe, the ICC will not ban Pakistan from cricket but the ICC will not force other playing nations to play in Pakistan because of safety reasons.