I follow computer chess avidly and so have seen lots of such French games where both engines get massacred as Black.* However, this doesn't mean the French is refuted. With engines as strong as they are, to generate decisive games, it's necessary to introduce highly dubious lines. Called "bias", this leads to openings where engines evaluate the starting position as +1 or more. Naturally, when the opening is so biased, the inferior side will be playing for a draw, without real winning chances (but if they can win with the superior side and draw with the inferior side, they still win the opening 1.5-0.5).
The idea that the French defense is refuted arises because engines often fail to defend high-bias French positions (see example, example). But note these high-bias French positions are high biased. The bookmaker intentionally inserts some inferior moves to create the bias. If you let the engines play the starting position from the French defense 1.e4 e6, you are still overwhelmingly likely to get a draw.
Here's an example of a high bias line.
1. e4 e6 2. d4 d5 3. e5 Nc6
Black's last move is a clear inaccuracy, because in the French defense it's imperative for Black to push ...c5. It still shouldn't be a game-losing blunder, however. This lets the stronger engine demonstrate its strength, and is therefore the kind of position that bookmakers give engines. These dodgy French lines are why the opening looks worse than it actually is in engine tournaments.
That said, it's worth pointing out that correspondence chess players don't rate the French defense very highly either. It's not that the French defense is busted, it's just that you'll be suffering for a draw.
*In engine chess tournaments, the opening is pre-determined, and both engines take turns to play the White pieces.
PS: I should add that computer chess moves really quickly. The example games above are only three years old, and yet Stockfish (the losing engine) has gained several hundred ELO in self-play. There's a high chance it can defend those positions against Leela now. As engines get stronger, bookmakers need to insert more and more bias to get decisive games.