There is never a penalty for hitting another ball on the green with a putt in match play, conceded or not. It is, to me, the least explicable difference in the stroke play vs match play rules.
Gotta be a leftover from the stymie.
When I started playing tournament golf it was exclusively match play and you couldn't lift your ball unless your opponent requested it.
The common practice of it was near the hole in an advantageous position was say, "Mark that and leave it."
The rule was changed a few years later, and tbh it still kind of pisses me off.
Match play is the only time golfers play directly against another golfer and their ball. Having different rules is appropriate and cool IMHO.
But then I'd bring back the stymie if I could.
As someone wrote more than 100 years ago, "The card-and-pencil boys are ruining the game."
IIRC the same source added, "You can't even get around in an hour and a half anymore."