Focused Launch x AnchorFM: cleanup code

## What

Cleanup code after AnchorFM sites are correctly assigned to Focused Launch flow

## Why

Some code is currently (and necessarily) hacky, while we transition Gutenboarding and AnchorFM sites from Step by Step to Focused Launch flow.

## A/C

Needs to be expanded

- [ ] (to be expanded) cleanup some hardcoded values forcing AnchorFM sites to be launched through Focused Launch flow

## Context

Some of the code to be cleaned up was introduced by #51001 and D57607-code

Start by reviewing the code introduced by #51001 and D57607-code, then trace the hardcoded values that force AnchorFM sites through the Focused Launch flow. The issue's acceptance criteria still need expansion; done means removing transition-specific forcing after AnchorFM sites are correctly assigned to that flow.

Written by the indexing model from the issue text.