Solved: In order to gain buy-in and motivate the team you must consult with

1. First a mail is sent to every team member with the details, ask them to prepare for a response for the situation
   1. Have a meeting scheduled
   2. Provide most of the informations necessary
   3. Avoid confidential information
   4. Ask for relevant recommendation
2. Have a one on one meeting (with everyone)
   1. Explain the situation
   2. Provide background
   3. Ask for their recommendation
   4. Key it in
   5. Give feedback and work ahead for them
3. Give a meeting invitation to all and ask for revised changes
4. Ask for a joint meeting
   1. Discuss the ideas
   2. Follow the 6 thinking hat method
      1. No interruptions, all ideas
   3. Then the ideas are discussed with pros and cons
5. Be open to say waht has been taken up and what key ideas are rejected with reason.
6. Identify the contribution of each person
   1. Accepted ones and also of the rejected ones

This motivates everyone.

People who are introverts and might not get their ideas out in a joint discussion can provide ideas on mail or during the 1 on 1 meetings.

Every contributor sees the logic and appreaciation for contribution, not necessarily for getting adopted but also for participation.

Then to take it further appoint the main idea holder to become the product champion.