lol why do you do this to us

Because I don't have a video game system and I need an outlet to explore my crazy ideas haha

The reality is outside the Gretzky deal its rare stars like this are traded.
The Gretzky deal was in a different era where money was more important then Cap and Prospects.
Now in todays league you dont get money without the Cap to sign players and Prospects to grow fan support around.

Honestly i think if Mcdavid left they'd want something to hard to pass up like Stamko's , Kucherov ,Sergachev , a couple 1sts atleast otherwise why bother from their POV
Otherwise they're giving a stacked team enough fire power to win the Cup for years to come without getting anything equal to his value given the 1st's are all late round picks it puts even more emphasis on receiving established talent .

TBL still is deep enough for that to work with Point ,Hedman,Cernak,Mcdonugh, Cirelli ,Gourde ,Killorn , Palat , Johnson ,Coleman and Goodrow
With enough cap left to re-sign Shattenkirk,Maroon and Bogosian if you see fit or target others .
With Mcdavid leading that groups offense they'll be set for years to come
they can call up Cal Foote also and put him in rotation to give your back end a injection of youth

EDM Gets a bonafide future HOF'er in Stamkos and Kucherov who's currently on Mcdavids level or atleast withing striking distance .
(wont last more then 3-5 years at that pace unlike McD which is why Generational Stars like him are so unique)
Sergachev is an embarassment of riches but would allow them to play 3 pairs at an equal 20 minute play more or less .(which is great for their young RD coming up like Bouchard.)

Without a severe overpay EDM fans will burn it all down and make their reaction to Gretzky being dealt look mature and sensible .
Their current GM's presented them with a 92% missed playoff rate since coming into their world of hockey and he'll feel the heat if after all that he gave away McD in a trade where they were not the clear winners today and in the next 3-5 years. Any team Acquiring McD would be doing so because even at 35 he'll be producing more then any Habs Forward has since Kovalev played. TBL can afford to make that deal because they're deep enough to get better after trading their top 2 stars the past decade same as they did after moving Lecavlier and St Louis