I've never seen any of the Trader Joe's or JosephsBrau beers in CT stores (I've most often been to Danbury and West Hartford).

Trader Joe's in CT used to sell a store brand of beer (at least an amber and an IPA) made by "State Line Brewing" which was contract brewed by Cottrell Brewing. Cottrell closed in 2022, so I assume that State Line is gone as well.

I would guess that Trader Joe's haven't done the paperwork to distribute their beers in the state and it was simply easier to contract brew a different line in-state.