The edition button doesn’t appear when you load up the game on disc. The Legacy version is only accessible on version 1.0 if you remove all the updates.
I tried to delete everything minecraft related from the system, loaded up the 1.0 and then installed the update but the button doesn’t appear either, both for my main and dummies accounts.
The version of the disk I refer to is this one https://images.app.goo.gl/xbAU4YkcSYnw13929
Thank you for your report!
We're already tracking this issue at MCPE-63401, so I will resolve and link this ticket as a duplicate.
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