It could be possible that is not what the writers wanted to do. I am also not sure if adaptions are writer's properties or if they need permission from the authors themselves. Then there is the possible issue of facing some sort of backlash when either returning to China after the work is done or simply applying to do more work in China itself.
I would also say that some of the Chinese "bromance" dramas based on BL material have been some of the most popular dramas, and probably financially rewarding. The Untamed comes to mind. Why risk trouble when what works is making money?
I do not see the trend of Chinese dramas turning BL into bromance ending anytime soon. I can tell it upsets you but your best bet may be to simply avoid Chinese bromance and look to the other countries you mentioned or simply accept that is the way things are right now and "tolerate" watching the Chinese bromance dramas.
Please do not misunderstand. I am not offering any defense for the government. That is a whole other discussion that MDL is not really equipped to deal with. I am just saying there are reasons why things happen or do not happen the way they do. I am a big fan of freedom, but know that it is not always universal.