Seriously? In a large scale disaster (hurricane, earthquake, etc) you would be irritated by getting a free text telling you...[whatever]
Why should he need to explain his reasons to you (or to anyone)? If he doesn't want to receive such a message on his phone, why shouldn't he be able to block or reject it? You'd rather force the message on him because you think it's a good idea, even if he doesn't?
If you are good, you will be assigned all the work. If you are real good, you will get out of it.