There are many topics we did not touch upon but would require our attention before being able to execute this solution. There is much uncertainty around those topics, but it would be crucial to get those right in order to make this initiative successful.
Change in architecture often leads to team restructuring or responsibility shifting. It would be interesting to invest in change management and look into team organisation (Inverse Conway Maneuver).
It would also be interesting to set goals and ways to measure progress to ensure meeting the architecture characteristics via the creation of fitness functions or other means to keep the efforts on track.
Involving Business into the ticket workflow co-creation to improve the reliability of the tickets handling and opportunities for better resource assignment.
Investing in more sophisticated third party solutions to replace parts of the system such as authentication or reporting for example to lower part of the development and maintenance burden.
Lastly, organising training might be necessary to bring the development team up to speed on the new practices of distributed systems introduced in this solution if needed.