Kompany helped Bayern Munich get improve however he is not the first choice for this team and they were about to hire some other coaches instead of Kompany. As far as I saw in the news the management of Bayern Munich asked Pep Guardiola and he advised them to hire Kompany and you saw so far Pep was not wrong about this coach in Bayern Munich but still even his good performance doesn't mean he can win the title on Bundesliga with Bayern Munich but still Leverkusen is very close to them and if Kompany and his player make any mistake, Xabi Alonso is there to take their place.
No reason why Bayern Munich will consider hiring another coach because for all i know, Vincent Kompany is still doing a good job for the club and they are Four points above Bayern Leverkusen who are second in the league despite that they have both only lost one game each since the beginning of the season but Bayern Munich will be the preferrable candidate for the trophy because since they have been in the top for so long, i think they won't want to lose the top spot to Bayern Leverkusen because if they give Leverkusen the opportunity to top the table, it will be difficult for Bayern Munich to reclaim it again because Leverkusen have been following them up relentlessly so any mistakes from Bayern Munich will probably lead to Bayern Leverkusen taking the advantage and possibly win the title. Pep Guardiola didn't make any mistakes by referring Kompany to Bayern Munich and even though many doubt his capacity at first, everyone is now praising him for maintaining a good consistency for Bayern Munich in the Bundesliga.