Easily. The generational d-men have been: Harvey -> Orr -> Potvin -> Bourque -> Lidstrom -> Makar.
When a player has a HHOF resumé at 23 years old? And he hasn't fallen off, he's actually still getting better?
At 23, Makar has one Norris & one second place finish, one Conn Smythe, one First Team All-NHL, one Second Team All-NHL. That's a HHOF resumé already.
Only 13 players in hockey history have won the Norris more than once; Every single Norris winner except Subban, Giordano & Carlyle is either in the HHOF or headed there eventually. And had Subban's back not gone out, he would have played long enough to make it himself.
As we speak, Makar has 4 top-3 finishes in Norris voting and he's probably going to win the Norris this year. But let's stick at 4. There's only a handful of players with more:
Raymond Bourque (15!!!! with 5 wins)
Zdeno Chara (6, 1 win)
Chris Chelios (6, 3 wins)
Paul Coffey (6, 3 wins)
Bill Gadsby (5, no wins)
Doug Harvey (8, 7 wins)
Victor Heman (6, 1 win)
Niklas Lidstrom (11, 7 wins)
Al MacInnis (6, 1 win)
Bobby Orr (9, 8 wins)
Brad Park (7, no wins)
Pierre Pilot (6, 3 wins)
Denis Potvin (6, 3 wins)
Larry Robinson (6, 2 wins)
That's the list of all players throughout hockey history with more top 3 Norris finishes than Makar... And Makar's just turned 26. I don't think it's crazy to think he might end up with 8-10 top-3 Norris finishes.