Several threads are already running regarding the sms / email from o2. You may want to look down the thread listing to get a faster reply to your question...
I did scan that thread and a few others first and it seems that the majority of posts are confirming they got the text. I am interested in the people that haven't, like me. 😞
They are just sending them out in batches, dont worry if you dont get it.
Keep an eye out here for when the next lot of text goes out and if you still dont get one call o2 customer service. To be honest they dont say a great deal.