In T253902: Variant tests: revisit edit completion for A vs. B, we decided that Variant A is the stronger variant of A vs. B, because it causes more newcomers on mobile to edit (while leaving the same number editing on desktop).
Until we deploy T246533: Variant tests: "initiation part 2" test (C vs. D), we should stop our Variant A vs. B experiment, and instead start giving Variant A to all newcomers.