No, a blatant establishment of religion would be the First United States Church of the Christian God, with a tax levy on all citizens to fund the church practices and membership required to hold public office.
Local county officials deciding who to and who not to invite to offer a prayer is the prerogative of a free people and is only an establishment of religion in the most ridiculously open-ended reading of the principle imaginable.
It is entirely possible for something to be consistent with the 1st Amendment, but still wrong & inappropriate for the government to do.