'are put in check' means a literal transition from static to dynamic. To win by Blossom Roses you have to move one of your pieces.
But 'moving one of your pieces' would not count as 'putting [the opponent] in check', unless you checked him with that piece, or by discovering a slider check over the square that this peace evacuated. So the expression 'are put in check' suggests that they should not be in check before, and that the check has to be caused by the move. While 'are in check' only addresses the static condition that should apply after the move, without making any suggestion as to the way it originated.
The examples you give in the chess.com blog show that you mean the latter. But the article here should be unambiguously understandable without having to consult chess.com, and your wording creates the wrong impression.
But 'moving one of your pieces' would not count as 'putting [the opponent] in check', unless you checked him with that piece, or by discovering a slider check over the square that this peace evacuated. So the expression 'are put in check' suggests that they should not be in check before, and that the check has to be caused by the move. While 'are in check' only addresses the static condition that should apply after the move, without making any suggestion as to the way it originated.
The examples you give in the chess.com blog show that you mean the latter. But the article here should be unambiguously understandable without having to consult chess.com, and your wording creates the wrong impression.