Como não recebi nenhuma resposta aqui, tentei na lista de e-mails do Git e aqui está a resposta que recebi :
On Sun, Jun 17, 2018 at 8:41 PM Shriramana Sharma <samjnaa@xxxxxxxxx> wrote:
> Do I need to execute any 'git submodule' commands separately even if I
> do 'git pull --recurse-submodules'?
Ideally you don't need "git submodule" commands any more, the rest of git
is slowly converging to have builtin submodule functionality.
> All I want is to stay in sync with
> the cloned repo.
That should just work with "pull --recurse"
> But if so what is the use of 'git submodule update --recursive' or
> 'git submodule update --remote --rebase' or such, which is somewhat
> confusing to me I'm sorry to say.
The git-submodule command was the first command implemented that
dealt with submodules. In the beginning there was no "git pull --recurse"
but the only way was to run "git submodule update" to change
the state of submodules. Now there are better ways to do that, such as
the recursive pull.
Hope that helps,
Stefan