NHL.com has TOI stats, which is nice as it means we don't have to infer usage from on-ice goal figures.
Leon Draisaitl does not regularly kill penalties. He's only averaging 40 seconds per game on the PK over his last 74 games (last year and this year combined). That's good for 164th place in PK TOI among forwards with at least 50 GP over that stretch.
There aren't many stars that PK today, but it should be noted that over last season and this season so far combined, Mitch Marner (1:59), Anze Kopitar (1:58), Sebastian Aho (1:46), and Alexander Barkov (1:46) all averaged more PK TOI than Brad Marchand (1:38). Despite that deployment, though, those 4 guys have a combined total of 7 shorthanded points in their last 287 GP. In other words, they are actually there for their defensive skills, not their offensive ones.
I honestly doubt that Gretzky would regularly kill penalties if he played today. It seems that the period of time from the early 1980s to the early 2000s was fairly unique relative to the rest of NHL history both for how much star offensive players played on the PK and for how much shorthanded offence they produced. In contrast, in pretty much every other era in NHL history the shorthanded points and shorthanded on-ice goals leaders are mainly full of checking forwards.
One of the reasons I personally think McDavid is closer to Gretzky and Lemieux than the adjusted stats suggest is because I don't give those latter two guys full credit for their shorthanded scoring. I just don't think it happens in other eras.