I think if you don't respond in a certain time accept or decline it accepts(not sure what the time frame is now) But if you don't want CEO's(and the benefit that goes with it) you can always set the setting block CEO's
This has happened for years. It's not a long time before they are auto-accepted, likewise I cant remember exactly, but only 12 - 24 hrs.
But really, if your country is good enough to have CEOs trying to get corps in it then be grateful for them, else raise your tax some to make yourself less attractive or yes, block altogether.