What is, or is not bluegrass music seems to be the question to which there is no answer... it just depends on who you ask. I've been in it, and surrounded by it my entire life. I know it when I hear it, I know what I like, never felt like it was my place to criticize what I didn't. I played in bands with people who did this all the time, and it bugged the daylights out of me. Like we weren't scratching and clawing for gigs too. Just my observation here. Every music genre has its militant traditionalists. On some level, I think maintaining traditional music is good. When it crosses the line into being exclusive, they don't need to show me the door - I'm out.
Here's a bluegrass group I like a lot, at a festival in France last August. This is a working band that's 'on the bubble'... the musicianship is super-tight, the show not quite yet polished, but you can tell they're going somewhere, and they want it.
I've been following ENG basically from their beginning but especially since lockdown, when they played to an empty bar in Madison Tennessee and broadcast on YouTube for Venmo tips. These days, they are about 7 years into a pretty good run. I've seen members come and go, and watched the core of the band mature into what it is. Whether they break out and hit mainstream remains to be seen... they're so close.