It's not one step away from doxxing at all -- in this case Lucky225 is not an unnamed source, that is actually his real legal name per his twitter [1] and the FCC database entry for his ham radio license (not linking that)
Well, I think they meant doxxing Joe, but also seems to be doxxing Lucky225 as you noted.
Once you look at Lucky225's Ham then you get an address. Of course, what is somewhat interesting is their listed address actually is located at Colorado's Division of Central Services building, which very interestingly is a way to obtain a confidential mail forwarding address. It says it is only to be used by victims of stalking/violence/harassment but who knows how well that is enforced: https://www.colorado.gov/pacific/dcs/acp-faq
Either way, I think SexyCyborg (well-known Maker) is quite right to call out HAM license as a vector for getting doxxed.
[1] https://twitter.com/lucky225/status/1258503072323526657