Hi all,
I normally am all for adapting to changes, staying on bleeding edges of emacs, Org, etc.
But FWIW, for this particular change to the "<s" Easy Templates, I'm in the camp of "It was working awesome, it was beautiful! Why change it?". For record, I understand the "why", but it just doesn't seem worth it in this case.
But the good thing is that this is open source, and you can backport the stuff you like from the original Easy Template code into your personal Emacs config (and then later adapt to the new way of doing the similar when you have time and motivation).