You guys, we are not going to see Darcy/Darcy will not find out about Lizzie’s vlog any time soon.
The point is that Darcy has no idea of Lizzie’s dislike up till the moment he proposes to her (or whatever the equivalent of that in the modern context is - asks her out?). So no, he won’t find out about her vlog, he won’t walk in only her vlogging, he won’t have a clue whatsoever that she doesn’t like him. Whatever Caroline is scheming, I’m pretty sure it won’t involve telling Darcy about the vlog because that would mean Darcy would watch them, which would mean he would hear Lizzie calling him a douche which ruin the climax of the story pretty spectacularly, I think.
And Darcy is “painfully shy”, he’s not about to have a vlog or declare his feelings for Lizzie to the whole internet. Or declaring anything about his life to the internet for that matter.
I only see him possibly appearing when we finally get to the Pemberley arc of the story (and I would love for Georgianna to show up when Lizzie is at Pemberley too) but any time before that, it’s highly unlikely. Or Hank and Bernie might just really want to torture everyone and keep Darcy hidden until the final showdown.