I don't see any discrimination in either of these, but "Early Career Dev" is definitely a new term to me and sounds a bit weird. What's bad about "Junior" to begin with? Everyone has to start somewhere.
All in all, I think everything should come with some context. People learn at different rates. Times change. What could've been categorised as a "Senior" 5 years ago might be more fitting for the "Mid-level" term from today's perspective.