The first one feels more natural. The typical flow is:
Define a Goal
Make a decision
In your first flow the user defines their goal: "Change my plan." Their next expectation will likely be "What are my options?" and once they've indicated their intent to pick a different plan, the confirmation reassures them their goal has been reached and ...
It's more of a question which i have in my mind (containing some answer to all other answers talking about security), that i add to the answer list... and i'm adding to the already asked question complexity.
There are so many ways we are reviewed here... but every single one has a flow, let review:
I won't let user to perform forget password.
The account ...