I found a little stumbling block when I first did this work, that I did not include in the article.
Firstly. If you enable group-based claims within Azure AD, you need to be running an up to date version of Microsoft AD connect software.
Only the more recent versions of the software provide the ability to replicate on-premise group names (rather just the GUID) to Azure AD.
This is only required if you want to use on-premise AD groups, to give access to the SSO Meraki portal.
Secondly, I found (and tested multiple times) that when the SAML token is sent to Meraki, yes the AD groups are also listed under the role claim.
However, the problem is that all the groups that the user is a member of, are sent.
From what I can tell the Meraki dashboard only reads the first role claim entry, not all of the lines.
In the article above, I have documented using Azure RBAC function within the Azure enterprise application, thus you can map an RBAC role (by value) to a group role claim, which enabled the SSO to work.
Also enabling you to give different Meraki rights based on user or group, the same as ADFS.
What is nice (in my opinion) is that you don't need to place a non-SAAS service dependency on your Meraki SAAS management.