Freiburg will face Hoffenheim, Union and Leverkusen which are harder than the fixture that Leipzig has.
Leverkusen will play vs Frankfurt, Hoffenheim and Freiburg.
Overall, I agree that Leipzig will probably end 3rd, the scenario that I have in mind is that Leverkusen will tie with Freiburg or lose there and Leipzig will jump or confirm the 3rd spot.
Leipzig and Leverkusen are 2 teams that are really hard to predict because both of the teams have basically the same form in the last five matches. So, a lot will depend on the opponents that they will be facing in their next matches.
Freiburg also has basically the same type of form right now. But they do have some tough opponents in upcoming weeks. Leipzig, on the other hand, is facing rather easier opponents. I expect Leipzig to finish in 3rd.