After editing the Onboarding Blueprint on Space Tools > Content Tools > Templates, the changes are not reflected on the pages that are using the blueprint via the Live Template macro.
The changes do not reflect because a page that uses a Live Template macro that points to a Scaffolding Blueprint will refer to Global Blueprints instead of Space Blueprints.
To properly edit the blueprint, go to Settings > General configurations > Global Templates and Blueprints > Onboarding > Edit.
Then, view the pages that were created using this Blueprint. You should be able to see the changes reflected on those pages.