There were endless moments in season 3 that would have been solved by reaching out to the progressive Borg collective from the season 2 finale. Not to mention that a few character arcs and character development moments that just seem suspiciously absent in season 3. So, is the entirety of season 2 not cannon or am I missing something?
Not retconned, but I definitely feel like they wanted to forget it.
Absolutely. There's a line in Season 3 that really stuck out to me. I can't remember who it is that says it, I feel like it's Raffi or Crusher, but they say "No one has heard from the Borg in 20 years." So either the events of Season 2 were extremely and heavily classified to this individual, the realization of them being a 'new Borg collective' is believed with utter certainty to the point of not even considering them Borg, or the events didn't happen.
There's nothing contradictory about the seasons, and they were written and filmed back-to-back. There's no need for a retcon.
Well, that's a decision you'll have to make for yourself. I happen to have grown up on DS9, and in my heart there's not much room for Worf's Wacky Adventures on Risa; people a couple years older than me tend to have performed some personal, private retconning of at least one episode of TNG's first season--if not more. And I have just finished the novel "Spock's World," and realized I wish I'd read it years ago and some of the thing's Diane Carey wrote in that exceptional book are better than the contradictory idea's Paramount officially introduced in later media.
What season 2 of Picard means to the producers is far less important than what it means to you--and if it inspires you to go back and watch TNG, you may want to jump straight to Season 2 of that show, as well.
