The academy hasn't been great during the last ~10 years and Bayern put in a lot of effort to reform/improve it (including building a new campus). A lot went wrong, but after 8 seasons in the forth division, the second team finally managed to get promoted in 18/19. The last ~2 years indicate that the management fixed the problems and it should show in the next years. In the past years there just haven't been many academy players, who had the quality to make it in the first division, nvm for a club like Bayern. In fairness at least part of the improvement comes from buying top class 15-17 year old teenager. I guess its up debate if these count as academy products or not, but I don't think anyone cares.
One way or another, Bayern is giving young players, who had little or no experience in (European) first divisions, a pathway into the team. Hopefully that continues with academy products and transferred youngsters.