Hi julieseto
I've posted a fairly detailed list of key concerns and questions around HTML Pages in SharePoint on the below blog post:
Publish rich and interactive content with HTML pages in SharePoint | Microsoft Community Hub
It would be great to get your feedback, particularly around how you and your customers are planning to govern and manage HTML Pages.
We can see significant potential in the capability, but it's also a major change to the SharePoint publishing model. For large global enterprises in particular, we believe significantly more guidance and controls will be needed from Microsoft around areas such as governance, branding, accessibility, multilingual support, responsive design and ongoing management.
One of our key recommendations is that HTML Pages should be disabled by default, with Site Owners explicitly enabling the capability where it's appropriate for their site, rather than introducing this new publishing model as enabled by default.
I'd be interested to hear how others are approaching this.