I'm not sure what you mean. If you have a Adobe subscription you get all Updates for free - exactly the same as for you mentioned example FL Studio.
The purpose and background of beta programs is to test the product before it is completely finished, to identify errors and to make improvements. When the program is finished after the test phase and a lot of time has been invested in development, it is accessible in the normal Creative Cloud. So as long as a program is still in beta and therefore in the test phase, these versions are still free, but only until the product is finally finished. So what would be your idea exactly then?!