The problem I have is that you imply that one player led to that success when I think that isn't the case. Yes, Lindholm's presence was certainly important for that line, but Tkachuk and Gaudreau also showed a ton of chemistry on their own merit. You can't discount that, especially when they never played apart from Lindholm to begin with. So who was the bigger driver? I don't think that is entirely answerable, but I think you can get a hint by seeing how Tkachuk-Lindholm was as a duo - they were good, but it wasn't until Gaudreau was added that the line really turned to magic.
There is also a ton of flip-flopping in this post. For example, you note that Tofolli's scoring binge is too small a sample size to judge from, but then you proceed to list Huberdeau as an example of a player playing his best hockey with Lindholm when they've had a 7 game run... like cmon. If you're going to make a point, be consistent. Otherwise its just disingenuous trying to fit a narrative you want to craft.
Tkachuk's first season in Florida was better than anything he showed in Calgary, especially that playoff run. 100 games isn't a small sample size either. Even with a terrible start, he's probably going to end the season well over a PPG again. If anything, Lindholm's game hasn't recovered with his loss...
Getting back to my original point, I really don't think he will be missed based off his play this year. If we're getting to intangibles that only hockey experts see, well I don't buy it. Besides his FO%, he's having his worst ES year in Calgary by a country mile. The degradation of his possession metrics in particular are concerning, and I just don't think you can look at usage as an excuse when he is at the bottom of the roster in that regards. This team, imo, is not an Elias lindholm away from contention or anything. I’d hope Calgary does what St. Louis did in 2017 with shatankirk or statsny in 2018 - trade the pending ufa and see if you can make a run regardless.