You don't need to opt to fill out one-page form for email or text notifications for case status updates. To receive email or text updates in your case, just go to USCIS website, click on "Tools" tab then from there follow a certain instruction to create an account. Once you find it, create your account (email, mobile number, your name, etc.). Once you create your account, (of course there's an email verification process before you can officially log in to your USCIS account) you have to log in then there is a certain instruction inside somewhere stating like "Add your case" something like that. Then you have to add your case (your case number of your application), once you add it, you can find some tabs on that case like "email notification (y/n)", "text notification" (y/n) ". click on the "Y/N" in those tabs and it will opt you to select where you want email or text notifications. This is what I've done in my N400 notification update to avoid getting crazy checking online updates to the USCIS site.
In my 4 years marriage, still it lacks some respect from my USC citizen coz he talks like I know less because I'm from Philippines and US is superior..what a #######