I could not find the whole timeline of this development in English, but you guys can use Google Trasnslate
1. The Military reorganized its assets (ncluding Lumpini Stadium) following mass shooting, Feb 2021
https://www.bangkokpost.com/business/2062627/army-overhauls-management-of-its-properties
2. Reopening of Lumpini Stadium with focus on entertainment and reform towards less gambling influences, March 2021 (Thai)
https://www.dailynews.co.th/sports/832110
3. The General's interview about Lumpini stadium, overseas television deals, removing gambling influences, refocus on tourists' ticket sales, female fighters, etc, April 2021(Thai)
https://www.smmsport.com/reader/news/338141
3. First Female Fighter in Lumpini, May 2021 (Thai)
https://www.smmsport.com/reader/news/338888
I think the Thai military finally realised that instead of taking tiny money from gamblers every other day, they could instead attract more revenues by making it more entertaining like other events on Thai national TV.
Will there be reform? I think gamblers will do their best to lobby the old style of judging to remain, but Covid hit Stadium Muay Thai so hard from tourists' ticket sales to reputational damages from Covid cluster starting in Muay Thai events. So some forms of reform need to happen.