When I browse to \\domain.local I see the expected DFS namespaces, but also see several printers. Can anyone explain how/why they show up here (and how to configure the printers to show up or not)? Thanks in advance.
Is one or more of your DC's also a print server? If so, that's why.
When you connect to the Domain namespace via UNC path you're going to be connecting to one of your DC's and you'll see whatever resources that DC has shared (SYSVOL and NETLOGON shares, etc). So if your DC's are also print servers (sharing printers) then you'll see those shared printers when connecting to the Domain namespace via UNC path, just as you would when connecting to any other server via UNC path. Naturally you'll only see the shared printers on the DC that the Domain namespace is being resolved to at that moment.
If you don't want to see those shared printers when connecting to the Domain namespace via UNC path then don't use your DC's as print servers.