I hate how the word "rebuild" has suddenly been replaced with "tanking".
I wouldn't take that kind of talk too seriously.
I mean realistically GM's can only do 2 different things.
0) trade player x for player y of equal value (that rarely happens)
1) trade "young" players/prospects for more established players when the team is in a win now mode. Technically they are sacrificing the future.
2) trade established players for young players and prospects, sacrifice strength now, for increased future strength.
I mean I remember Buffalo as having a wicked team a while back (Vanek, Briere, Drury, Roy, Pominville) that was the year they did really well. Then they got poached in FA. It gutted the team. Then they slowly slipped into being bad. Then they got an owner who tried to buy players to make them good again. Finally once that failed too, they realized they needed to get draft picks and actually create good players themselves. Its just sorta how things go.
In Toronto they have enough money they have been believing they could buy their way out of problems for alot longer than teams like EDM, and BUF. So they are delaying the inevitable.
EDM never really "planned" to tank at first. They were shunned by FA's and even their offer sheets were matched. Their prospects did poorly, and they slipped. Their rebuild is going poorly because they drafted no D-men. Its a huge mistake.
None of these teams are tanking per say. But when you double down on a good idea: Sell assets now (going to UFA) to get some picks etc. Then that could be taken as "being bad on purpose" mostly its being smart. The only few teams that are "good" and didnt totally become crappy first are: Det, Bos.... Anyone else??