Is it okay to pirate a game if the developers shutdown?

Legally? NO… The game's copyright & game IP is still owned by somebody, so you're still breaking the law. The rights holders can still sue you for software piracy & copyright infringement, although it can be a challenge to determine who the legal rights holder(s) are.

This is why it's been difficult or nearly impossible for some games to get re-released, remastered or get an official sequel as a result.

Philosophically? It can depend on the developer's stance here. Some developers are a bit tolerate of software piracy in places where the game can't be legally purchased for some reason. The reason for the tolerance is that the developers want people to enjoy their game & consider piracy more as a "service issue" (as in "lack of customer service") that their publisher is not resolving for some reason.

As you mentioned Minecraft: Story Mode… Effectively all the games that Tell Tale Games have made falls into this legally & morally grey region, as those games are no longer available to purchase legally to new customers. Those who have previously purchased games by Tell Tale Games may still have access to those games on the platform they were purchased on, but those titles are subjected to the platform's Delisted / Sunset Policies… Which may limit how long those games are available (as it's typically hidden within the platform's ToS).

HOWEVER, as there's physical copies for some of Tell Tale Games's library… There's still a somewhat viable legal option to play the games, but it's going to be an increasingly difficult option to pursue (as the resale prices on the secondary markets will likely increase because of the delisting, especially for desired titles). As a result, there's going to be some initial resistance to piracy.

For the general gaming public (the players), while there's going to be a debate among the public on the aforementioned issues… The typical consensus will that most will be OK with piracy in this regard. HOWEVER, this consensus will only last as long as there's no viable legal option available to obtain & play the game. Once viable legal option becomes available (like a game getting relisted, remastered or remade), the majority of the public will shift their opinion towards that legal option.

Therefore, it's more of a question of your conscience here… If you're don't mind the debates on this, you should be OK.

No, the copyright is probably vested in the owners not the developers.

Ethics are subjective. I personally see nothing wrong with pirating any movie, tv show, comic, or video game. If i want to support something i really like, i will buy it. But otherwise i'm not going to buy something if i can just as easily get it for free
and when it comes to pirating games from shut down studios or that are no longer in print, there's absolutely no problem at all because buying a used copy off of ebay gives the developers the same amount of profit as if you just pirate the game: $0. The only person you benefit when buying a used game is the person selling it, not the people who made the game

Copyright infringement is illegal, by definition. Intentionally infringing copyright is not "okay" and you can be sued if not also arrested.