Non-SharePoint Content inside Modern Experiences, only possible for companies close to Microsoft?

Do companies closely related to Microsoft have access to technologies us mortals do not have?

IN https://www.visualsp.com/products/visualsp-office365/?utm_source=hubspot&utm_medium=email-hubspot&utm_term=here&utm_campaign=training-for-office365-soft-launch&utm_campaign=Training+for+Office+365+&utm_source=hs_email&utm_medium=email&utm_content=39655273&_hsenc=p2ANqtz-_M0Vbq5O6k83uhsQtxgi1ww76wVP9p-1-ww8yLy_sXQXvLu5jRL52RqSTi54FAQLN2VHJg3SNWe74emCSa6YWfH_5Cnw&_hsmi=39655273I see non-SharePoint content being displayed on top of Modern Experiences, which, according to the message from Microsoft can not do branding or run script