Epic Planning/Breakdown

However, the desire of this organization is that the whole team participate in every step

What problem are they trying to solve by this organizational constraint? It might be better to promote self-organization regarding who does what and when, and clear accountability for the outcomes.

You could potentially do this during Product Backlog Refinement, however you still need a Product Owner to collect all the requirements. Epics and Features should be written from a business perspective and then you can spent time all together to break down the work in items, or T-Shirt size the stories. Management might have to challenge them if they are not happy with it, but not force them. The Scrum Master should encourage them participate

@Ian Mitchell - I'm new to the organization, but I believe it's to foster inclusion of the entire scrum team in defining the work product. They want everyone on the scrum team to weigh in as stories are written but also as higher-level items are dissected into features, etc.

@Prodomos Lilitsis - I neglected to mention that I'm an SM for one of the scrum teams in this organization. We have been handling this higher-level discussion in refinement. However, when we're refining items at the epic level, the team does not participate much. When we refine at the story level, folks participate much more.

I pulled this statement from the Scrum Guide section that describes the Scrum Team

Scrum Teams are cross-functional, meaning the members have all the skills necessary to create value each Sprint. They are also self-managing, meaning they internally decide who does what, when, and how.

If the organization is going to force that everyone participate in all steps, they are not honoring the Scrum Value of respecting the Scrum Team to self-manage themselves.  Are there specific reasons that the way your team wants to operate is causing issues with their ability to deliver value?  If not, then why does the organization feel the need to dictate how the team operates? 

What you are describing is a Scrum Team that has self-managed, self-organized in a fashion that they feel comfortable with and in which they feel that their time is being used for the most value.  They have determined ways that refinement can take place to their advantage. The Scrum Guide gives this description to the activity of refinement.

Product Backlog refinement is the act of breaking down and further defining Product Backlog items into smaller more precise items. This is an ongoing activity to add details, such as a description, order, and size. Attributes often vary with the domain of work.

Notice it doesn't say anything about everyone on the team being involved in all refinement activities?  

As a Scrum Master, I would question the organizational requirement.  How does it provide benefit to a team's ability to deliver value?  Are the specific issues that have occurred that this requirement is expected to address?  Is it a systemic problem across all teams or has it only been an issue for a one/few? 

While the Scrum framework does not provide you with a process to follow, it does provide you with some guidance that make a lot of sense.  This situation sounds like a great time for the Scrum Masters of your organization to come together to fulfill your responsibilities to the organization.

The Scrum Master serves the organization in several ways, including:

• Leading, training, and coaching the organization in its Scrum adoption;

• Planning and advising Scrum implementations within the organization;

• Helping employees and stakeholders understand and enact an empirical approach for complex work; and,

• Removing barriers between stakeholders and Scrum Teams.

There are no constraints in Scrum. The scenario cited here seems to be from a big organization, and big organizations can use Scrum with the help of Scaling framework - Nexus, Safe, Less.

In all ways there is no compulsion that everyone needs to be present in story refinement.

All frameworks says that all relevant stakeholders/ representatives needs to be present in refinement process. An epic needs multiple session to reserch/identify impact on various teams,components/features . And one or more representative can get involved in epic refinement activities. Ideally team capacity's 5 to 10% can be involved in refinement activity, as its a ongoing and regular activity during the course of time. Refinement needs a considerable effort and time of Stakeholders/PO/BAs, scrum team.

Also sometimes due to remote teams its not feasible and time consuming to involve every member of team to get involved into epic refinement.

Example - if a epic has details relevant only product A (credit card), and there is clearly no impact on product B(Saving bank account), then there is no need to involve product B team in refinement.

Product B team can be asked for any inputs , in case they have, or any possible impact they might have.

Thanks, @Daniel Wilhite! I just started at this company a few weeks ago and am still learning their norms. This is one of them. I don't want to automatically suggest a change without first giving things as the team is used to them my best effort, but I generally also do not believe that everyone is needed in refinement (Epic or otherwise) 100% of the time, every time. 

@Jaya Agnihotri - It's actually a small organization, but they're growing, and I believe this is a holdover from when teams were small and everyone needed to be involved in everything because there just weren't enough people to specialize in one area or another. Now we have all of the scrum roles, and I feel like we could give the teams some more autonomy to decide some of these things for themselves.