Dortmund gave it their all since they performed well in the first half and tried to score goals, but they didn't have the luck. Based on their performance that night, I believe they will likely win Real Madrid because the ball did not like them. If Dortmund sack their coach, it will be a shameful thing for the president and anyone who gives him bad advice will not want the team to improve next season. However, with the ball they played against Real Madrid yesterday, I am confident they will still do well next season and compete in the Bundesliga title and the champions league, if they didn't make any changes in the team. Am thinking next season Bayern Munich and Dortmund will fight for the tittle next season Leverkusen will not compete with them next time because am sure they won't try to make any mistake like last season, and defeat Bayern Munich is just Dortmund that try and make a draw with them.
Dortmund did their best like you rightly said and it shows that their form is intact of which by next season of everything remains constant with some improvement, they are going to do much better and even become top contenders both in their domestic league and the champions league aswell because because they appears to possess some levels of consistency which will be of an advantage to them.
Bayern Munich may not even be really strong enough next season to fight Dortmund and Leverkusen, going by all that is happening around the team in recent times, I think they will do more of getting the team back in a solid shape by trying to get everything in the right place and form with their new coach whom some are seeing like such that won't be able to really get them to doing much because it's assumed that he doesn't have a very vast experience yet as a coach as he's been with average teams alone mostly so the chances that the will be able to get to compete high at the levels of these two teams isn't wide enough.
Leverkusen and Dortmund are appearing like they have attained a different level of vast stability in the bundesliga such that Munich may not be able to really compete in the coming season due to their recent form and the fact that they will be having a coach Change sooner, with Leverkusen especially they are not going to change their coach and if they aswell retain all their players, they can be sure they will be able to maintain a certain kind of strength in the bundesliga next season.