PUT A LARGE NOTICE!!!!
At the top of the new templates saying
WARNING!!!! This template can't use widgets so use old templates if you need to embed code.
Thank you for coming to the community with your request. You're correct that the new editor does not have HTML access, so it would be unable to include third-party html widgets. I'm adding you to the feature request to give HTML access in the new editor. If you tell us what widgets you were wanting to install, I can also start a feature request for better integration with those programs as well.
I needed to connect to Eventbrite.
The point I wanted to make strongly, is that you need to put a warning box up before people start working in the new templates telling them that there are some very important features which aren't available to them.
My email shot was useless without the Eventbrite link - so had to start all over again at the end and go back to our old template.
Thank you for sharing this feedback on our email templates. I'm sorry for any confusion there may be with connecting to your Eventbrite. Being able to connect directly through our template is a feature request I would be happy to pass on to our engineers. In the meantime, as a work around I suggest connecting through a clickable button or through a text link.