My first game jam was about 8 year ago and it had nothing to do with corona, and it was by the way a .exe file, and yes WEB builds was also normal then. There is more then time enough if everybody understand that they have to do more. In my eyes is self promotion just a bad excuse to get all the attention. And when we give a little or no attention to most of the games, then the interest in doing anything will of cause disappear, so you could help you self by making them interested in being more a part of the game jam. And then will your self promotion not be necessary.
I know you don't like I am saying it, but it is about creating a culture where everyone (or at least most people) take more part of the game jam. And self promotion do not help here.