The “launcher” will no longer be used with any future releases and can’t be used to install 26.05.
To install the 26.05 released version (or later), you need to download it from the main site – Anki - powerful, intelligent flashcards . See also: An important note about updating to 26.05 .
For now, you can assume that the beta-release process will go back to what it was before – an announcement in Anki > Beta Testing and a separate download.