Nylander is currently tied with
Auston Matthews for 2nd place with 9 overtime goals, behind him is Tomas Kaberle with 7, and then you have Clark, Thomas and Tavares each having 6. Sundin currently sits atop the totem pole with a whopping 14 OT goals, so the current generation of players have some work to do as they look to overtake the record.
With how the overtime period has changed since the NHL adopted 3-on-3 play back in 2015-16, it's no surprise to see players from the current generation rapidly climbing the ranks. With 2 less players on the ice than we saw during the Sundin era, it means more touches for star players. Sundin's 14 goals are even more impressive when you consider the old overtime rules.
Nevertheless, Nylander is now just 5 goals back of Sundin and it makes you wonder if he can get to that illustrious first place pedestal before the season ends with his contract expiring. If he doesn't return next season, which seems highly unlikely at this point, then it will be up to Auston Matthews to dethrone Sundin. However, if/when Nylander does sign, he may very well be the favourite to best Sundin's record, which is wild to say since he shares a team with arguably the top active goal scorer in the league.