What are strong reasons to switch from RFA to EMA? From the presentation so far it seems to me EMA occupies more or less the same space as RFA. Perhaps a with a little higher level of abstraction. But I'm sure I'm just missing things.
EMA is easier to learn and support and a bit faster than RFA. It's open-source. And it is TR's strategic API.
If you have an application written with RFA, the time to move it to EMA is when you are rewriting it (or parts of it) for business-driven reasons. If you are adding functionality, or doing a major technology refresh such as an O/S migration, you should consider migrating the application to EMA as part of that. If you're writing a new application, or a major new version of one, that is also the time to use EMA. Your RFA developers will learn EMA quickly and easily.
You don't need to launch RFA to EMA migration projects just for the sake of it.