Assuming that the email/message that you received from the university in question is legitimate, it is generally normal to receive such emails/messages. It is important for universities to attract the largest possible number of students to study degrees within the range of degrees that each university offers. In addition to more traditional advertising means (for instance, advertisements for universities that you might see on social media), such correspondence also constitutes a way through which a university advertises itself and the programs that it offers. This means that it is solely a marketing approach that the university is adopting and has no effect on your UAC preferences. If you are certain that the email(s) and message(s) that you have received are legitimate, you may wish to safely ignore them. If you suspect that they may not be legitimate, be sure to block and remove them. More importantly, avoid interacting with them in any way if you believe that they are suspicious.
From personal experience, MQ was one of the universities I applied to when I did my HSC and while it was expected that they would send emails notifying me of my application outcome, they sent me a few, general emails after I enrolled at WSU towards the start of my first semester, which were unrelated to my application. I also recall receiving an email from USyd more recently advertising a particular Master's degree. While I am interested in pursuing postgraduate study at USyd specifically, I did not make any application or contact the university about this in any way. From this, I can deduce that many other people are likely to have received the same (or a similar) email.
I hope this helps!
