From my point of view and much like you say, the interesting, groundbreaking work has moved outside strict deep learning research. I mean, I sure would think so, but here's the website of the International Joint Conference on Learning and Reasoning, that brings together a bunch of disparate neurosymbolic and symbolic machine learning communities for the first time:

http://lr2020.iit.demokritos.gr/

This is an active field of research with plenty of space for new entrants and full of intersting problems to solve and virgin territory to be the first to explore. I'm hoping we'll soon see an influx of eager and knowledgeable new graduates disappointed with the state of machine learning research and willing to do the real hard work that needs to be done for progress to begin again.