Is Shirobako good? does anything happen or it's just subtext like Love Live? and talking about subtext, Renai Lab is also only subtext right?
I would say it's really good if you want to know more about the anime industry in Japan.
I have the impression to have secrets being revealed to me about how things work.
But definitely not yuri- I would say. There is no romance in it as far as I can see.
And to be honest, it's good like that.
Shiraboko has some light yuri, not at a very high level though. No yuri means plenty of in-your-face boy x girl, or het harem, neither of which is happening in the show either. Plus the poster was also asking for subtext. A romance label can only be applied if the show has very canon yuri romances, which is why some people use subtext, as character relationships can be satisfying in a yuri way to some, but can't be construed as "proper" romance, as there is no canon confirmation.
Going by this, at least, tends to net me enough, to fulfill my yuri show needs! :D