Right, if the Vikings beat the Lions but don't take another loss they are the #1 seed and win their division.
I don't think the 49ers are much of a threat to the Lions (but you never know). And a Bills loss still wouldn't give Eagles the tiebreaker (which is conference opponents).
By the same token if the Eagles have to lose one more game it should be to Pittsburgh not an NFC team. But that would still open up a bigger gulf.
The new format really still is a bummer. Right now Lions would have bye and Eagles face Commanders 2/7. But Detroit could also still got knocked out by Minnesota or Green Bay in the playoffs and then Eagles would have home field.