I think that was a good goal, but ... I definitely get why Keefe didn't challenge.
If they'd just stuck with the original call, good goal, I really don't think there's enough there to overturn it - puck wasn't clearly covered, JT goes after the puck and has minimal contact with Allen. But because they switched the call to no goal, I also think there's a good chance there wasn't enough to overturn the no goal, as there was a little bit of goalie contact by JT, and Allen had it sort-maybe covered for a split second.
To me this is "on the line" between goal and no goal, and much more on the goal side than the no goal side, but when you can make even a weak argument that the call on the ice was correct, it tends to stand. Unfortunately they changed their mind (IMO wrongly) about the call on the ice, which was crucial, as IMO this was a "call on the ice stands" situation either way, neither goal nor no goal would've been overturned. If Keefe challenges that, chances are the challenge fails, and suddenly we're on the PK and giving NJ a chance to tie the game.