Is it permissible for the Friday sermon to be delivered in local dialects or in classical Arabic?

The Friday sermon is an act of worship that is not permissible in colloquial Arabic. However, if there is no one fluent in classical Arabic, and this leads to the attendees understanding the sermon in colloquial Arabic, then there is no harm in that. And if the attendees do not understand Arabic, there is no objection to translating for them after the prayer or clarifying what is necessary in their dialect.