In my opinion, on the contrary, Leipzig's place is still not safe for next season's champions league because Leipzig will play Bayern Munich this week and their chances of winning are not even there. So I think Leipzig will only be able to get an additional 3 points against Schalke later and if Union Berlin or Freiburg each get 6 additional points in the remaining matches then Leipzig will drop to 5th place in the standings.
But indeed the result is still too complicated for some of these teams and all possibilities can still happen. I think Leipzig's main focus is now only on the game against Schalke and if they can win that game then it's pretty clear they will appear in the champions league.
Why you think that Leipzig has no chances to win against the coming game against Bayern Munich ?
There is for sure the chance that they can win that , specially against Munich and the current situation ,
with a win there that they can help Dortmunds chance bigger for the title are enough motivation for them.
And if the only playing a draw that would be good.
Yes, on a head to head basis, of course, Bayern Munich is always ahead with a win, but indeed there are often draws in the matches of these two teams. Maybe it would be more accurate for me to say that there is not no chance, but there are indeed very slim chances for Leipzig to win against Bayern Munich. But if these two teams end in a draw, of course it will be a very good result for Leipzig because it is certain that they will secure the top 4 places, but I only think about some doubts regarding the result later.
On the other hand, Bayern Munich will indeed be at a disadvantage if they lose to Leipzig because Dortmund will close this season with the Bundesliga title. Well, let's just take a look at the match this week, for sure there will be unexpected surprises for most people.