As a Canuck fan, I think this proposal is horrible for both teams and totally unrealistic.
Firstly, from the right team, I think Chicago could get a better deal. Others have already commented about it being bad for Chicago so I won't dwell on that. I also won't dwell on Kane's no move contract and whether he would or wouldn't waive for the Canucks.
Secondly, Vancouver is not the right team to be trading for Kane. Imo the original poster is being fooled by a lucky playoff run fuelled firstly by St. Louis being really weak at the time of the playoffs and secondly by really, really hot goaltending, firstly from Markstrom (who is gone and replaced by Holtby who is three years past his all-star years) and secondly from Demko (who was so hot it isn't remotely sustainable.)
The Canucks were soundly outplayed by Vegas and before that by a St Louis team that wasn't playing its best. Perhaps the OP forgets the Canucks were outshot by St. Louis 229-166 (ave per game 38-28) and by Vegas 275-169 (ave per game 39-24). They were really lucky to advance to play Vegas. They were on the bubble as to whether they would have made the playoffs in a normal year. There were not anything close to an elite team.
Yet the OP wants to make the ultimate "The future is now" trade. The Canucks already gave up this year's first, a second, a third and a good prospect in Madden just to get into this year's postseason where they simply weren't good enough to have a chance to compete for the Cup. Now the poster wants to trade two of their three best prospects and another first round pick, completely trashing the future in an attempt to try to win a Cup against long odds sometime in the next two or three years.
It seems totally unrealistic to me. Really, I don't want three years of the Canucks being good but not good enough, followed by several years of misery. It isn't the way to build a stable winning franchise.
Thirdly, even getting rid of two years of Eriksson's cap hit and one year of Sutter's, in 2021-22 the Canucks would be left with Kane @ 10.5, Myers @ 6, Schmidt @ 5.95, Pettersson at maybe 9, Hughes at maybe 7.5, Boeser/Horvat/Miller @ a combined 16.625, Roussel and Beagle @ a combined 6, Holtby @ 4.3, Demko at whatever he gets (if he beats Holtby out for starter it could be substantial but let's say 4.3), 3.5 for Ferland until the opening day injured list, $3.366 million for Sven Baertschi (or $2.292 million without filling a roster spot), very possibly $1.7 in deferred bonuses for the performance of Pettersson and Hughes in 2020-21 and $3.035 for the retired Roberto Luongo, all against a salary cap which is likely to stay at $81.5 million again as it is extremely unlikely we'll see fans in the seats for an 82 game 2020-21 NHL season.
If Baertschi were still in the organization but not on the Canucks that would leave, going into the opening day of the season, $2.5 million to fill 10 spots on the roster. Even with a roster of only 20 players plus Ferland it leaves $2.5 million to fill 8 spots on the roster, less than half the NHL minimum per player. Even if they somehow get rid of Ferland, that leaves $6 million for 11 spots, still below NHL minimum per player with nothing left to cover the inevitable short term injuries.
Note I haven't even included anything for Virtanen, who would be making considerably more than NHL minimum.
Even for 2020-21 it is very, very close. Right now Capfriendly shows about $46.592 million on 13 forwards who don't include Virtanen or Gaudette, $21.792 million on only six defencemen, $5.35 million for 2 goalies, 1.033 for buying out Ryan Spooner and $3.035 in recapture penalty for Roberto Luongo. Add to that the $1.7 million in deferred bonuses for Hughes and Pettersson for 2019-20, add $10.5 for Kane and assume $3 million for Virtanen while removing Eriksson and Sutter and that gets the Canucks to $82.627, already over the cap and they still need a 7th defenceman and enough space to cover short term injuries, even if willing to go with only 22 players on the regular roster. I suppose they could make the opening day roster if Ferland is hurt by not having a 7th defenceman and papering two of Pettersson, Hughes and Rathbone down to Utica for a day (imagine the reaction!) but heaven help them if Ferland is healthy enough to make the roster if anyone else gets hurt and has to be provided for without getting long term relief-at any time in the year. (Even then I haven't provided for Gaudette, who would put them further over the cap limit.)
So what do the Canucks do? Do this proposal and give up some additional high draft picks to get rid of the contracts of Beagle, Roussel, Ferland and Baertschi?
Strangely, as much as fans have pointed out the deal not making sense for the Hawks, it is actually worse for the Canucks. At least in the Hawks case the cap space doesn't make it impossible to make it work and it points to the future. In the Canucks case the cap makes it next to impossible to work the deal and it makes the future look really, really bleak even with their young stars.