Can I squash the merge created by "git subtree add"?

[Kannan Goundan]

When I do a "git subtree add", I get two commits.

    df7e8f5 Merge commit '6de34775ea846c90e3f28e9e7fdfe690385c068b' as
'go/src/gopkg.in/ns1/ns1-go.v1'
    6de3477 Squashed 'go/src/gopkg.in/ns1/ns1-go.v1/' content from
commit 1d343da

Unfortunately, in the environment I'm currently working in, merge
commits aren't allowed.

Is it safe to squash these two commits into a single commit?  Will
future "subtree" commands still work correctly?