In general, there is no limit to innovation or what is technically possible. This applies to all things without exception. The main inputs for this are time, human capital and money. I know this from first hand experience during my career.
I have no first hand knowledge of film manufacturers' activities. I do believe that development is going on. It depends on your definition of "new emulsion technology". In my definition, small tweaks to old recipes in order to improve processing or environmental impact, are new technologies for me. I believe this is happening at places like Kodak (Ektachrome 2017/2018) and Ferrania (latest P30).
I think it will be pretty hard to find non-public information about actual projects underway, who is working on them, how much money is budgeted, and planned introduction dates. If anyone had this information, and posted it in a public forum such as this, could find themselves in a compromised legal situation.