This has nothing to do with Kreider because in your scenario he's gone and you've replaced him with a player drafted in the top 10.
I'm trading Kreider for assets to move up in this year's draft. I'm also, by doing so, retaining flexibility for future cap moves over keeping a player that I project will eventually (2-3 years into a 7 year deal) be on my third line.
I'm just trying to get a sense of when you think this team is ready for prime-time because Kakko and rookie being 27ish is like 8-9 years away.
Well, assuming the Rangers would do what I'd do (trade Kreider, and probably also Georgiev and maybe another piece or two like Skjei and Fast, but keep Buch and Strome on shorter deals)....
I'd be projecting next year ('20-'21) that they are a playoff team but not a contender, with Chytil and Kakko taking a substantial steps forward (40 points and more consistency overall?), Kravtsov probably warranting a call up to the big club, and Buch, Strome, and the rookie ("unspecified prospect") adding enough, combined with improvements in defense and a full year of Shesterkin.
The following year ('21-'22) it's probably more of the same as Kakko, Chytil, Kravtsov and the unspecified prospect remain maturing, Zibanejad and Panarin probably at their peaks, but losses of Staal, Smith, Lundqvist, etc, leave us more talented and without the baggage of those old players, but also low on experience.
But then I would think the following year ('22-'23), when you've got 21 year old Kakko, 22 year old Kravtsov, 23 year old Chytil, 31 year old Panarin, 29 year old Zibanejad, and a D+3 unspecified prospect, plus a defensive core of 24 year old Fox, 29 year old Trouba, 27 year old DeAngelo, probably Miller, Lundkvist, Robertson, up with the club by this point, you have a contending team if not a team that's a favorite to win.
As we move from '22-'23 towards, say, '25-'26, Panarin and Zbad are gonna drop off. At this point, it's pointless to have projected a with literally ANY degree of accuracy a roster composition, but the HOPE would be, you still have a core of 24-25 year old Kakko, 25-26 year old Kravtsov, 26-27 year old Chytil, and this highly drafted unspecified prospect from the 2020 draft that are forming the core of a top-6 that is still lethal, also perhaps supplemented with other players we've drafted since then.
The most important takeaway is, if Kakko is an 80-pointish player, but Chytil and Kravtsov are only like 60 point players, their spots on the top 2 lines are well deserved, but it's not really enough. You still need one more 60-70-80 point player there to likely have a deadly top-6.