Why do you believe the data collection is not GDPR compliant?

I think that the site is very clear on how my data will be handled and what my email will be used for (sending me 3 emails).

To quote from your pasted link: 'The new regulation requires that brands collect affirmative consent that is “freely given, specific, informed and unambiguous” to be compliant.'

I submit the data freely to receive the information stated on the page.