Holacracy Community of Practice Archive, 2015-2019 Community Holacracy Web Site

>what do you think, is it a valid objection during governance meeting, that there no one to fill the newly defined role.

Unless the objector can clearly state why creating the role will cause harm, it is not a valid objection. 

And as creating a Role does not bind any resources, it will probably be hard to argue this point - but that's not for outside people to judge.

In any case, in practise, you can always move to integration: the tension that lead to proposing the new role to be created still needs to be addressed. The objecting partner has to come up with an alternative suggestion.