Yes, I am employed by PDFTron. I've been leading this project since early 2019.
As Nick says the project is open source (https://github.com/PDFTron/webviewer-ui).
Express is available under under dual AGPL/commercial license ( similar to iText and lot's of other popular OSS )
If you are talking about info on the site & git, we are working on it. There will be many changes over next few weeks. Stay tuned :)
The question was about your claim that it was already licensed under it. Apparently it's not, but you're "working on it". Umm, okay.