In my en passant puzzle Paul morphy would have played the pawn move to checkmate his opponent in some part of his career and then had his opponent take the pawn in another part of his career to avoid checkmate
Just an oddity of rule change at the time
What I was meaning was that in one part of Paul morphy’s life he would have been able to checkmate in my en passant puzzle. But in another part of his life it would NOT be checkmate because there was a legal move to get out of it😊😊😊😊
The move was originally invented in 1561, and officially accepted to the rulebook in 1880 according to wikipedia.
This description is incorrect (and it isn't exactly what Wikipedia says, either). En passant was pretty much universally accepted since the 1500s, and included in nearly every rules list. The last holdout was Italy, who finally added it to their rules in 1880. The Italian rules had other strange differences, such as how castling was executed. It was for their 1881 national championship that they finally decided that they should get on board with the rest of the world.
Hey, my Oxford Chess Companion after all these years finally proved itself useful!
In fact, en passant was so universally in effect, that the "Italian" rules prior to 1880 actually included a rule ("passar battaglia", or "avoid the fight") saying you can't take en passant. Apparently, if you decided to play by "Italian rules", you were agreeing on passar battaglia, and the expanded castling rule (where you can choose g1 or h1 for the king, and f1 or e1 for the rook). The existence of the Italian rules only strengthens the fact that en passant was the standard way to play chess for hundreds of years, and the Italian rules were a sort of regionally popular variant that finally disappeared in 1880 - mostly because the Italian castling rule gave white too big of an advantage.
It also isn't correct to say that en passant became "official" in 1880, because there wasn't a FIDE yet in 1880. Official worldwide rules for chess didn't come into existence until 1928 (FIDE was formed in 1924) and didn't really stabilize (because of differences in language translation) until the 1950s.
Just imagine a GM playing an OTB 32 board simulation if this change you are proposing was implemented.
"Hmmm, on board 16 they just played pawn c7 to c5 but did they play pawn e7 to e5 earlier? I need to know or my en passant would be an illegal move..." 
Bots from Chess.com never executed en passant in my games