Q: Is that possible to change the affiliation name after the final proofreading of the manuscript has completed?
Thank you for this pertinent question. Yes, it is definitely possible to change this even if the manuscript has undergone final proofing. Accurate affiliation information is very important; therefore, please inform the journal editor of the change, requesting them to incorporate the revised version. In some journals, even once the article is published, the updated affiliation information can be displayed as a post-publication note. Please write to the editor's office explaining the situation and requesting a revision. You will need to provide evidence that the change has been agreed upon by the author in question (an email communication, for example).
Hope this helps.