At this point I think the Leafs are playing with house money.
The Leafs are the road team. They finished with 7 less points than Boston. They matched up against the team they had the worst regular season record against and they lost Nylander for 3 games and Matthews for (likely) 3 games. The Core 4 have played a total of 40 minutes in the lineup together this series and the series is still going 7.
If you told me before the series the Leafs would lose Nylander for 3 games, Matthews for 2-3 1/3rd games and the core 4 would play a total of 40 minutes together against the Bruins - I wouldn't have predicted 7.
Boston should have won the Atlantic but I believe they tanked for this matchup because they outscored the Leafs like 4:1 in the regular season and swept the regular season series. Now the Leafs, with all their injuries, are still going 7. All the pressure is on Boston right now.
For Toronto, changes are going to be made regardless. I can't imagine Keefe keeps his job unless the Leafs go to at least the conference finals and without Matthews that's going to be a tall task. Changes will happen this offseason.
Win or lose, I'm shocked this Leafs team, without Matthews and Nylander for half the series each took Boston to 7. Boston was the team that was leading the Atlantic nearly all season until the last game of the regular season. The Leafs aren't the one blowing it to a team with 7 less points than them - they're not expected to win, nor were they the favourites and the Leafs at least can use the injury excuse. Boston choking back to back to a depleted Leafs team would cause much more chaos.