They likely won't help with ranking.
Just my opinion, but I think it does not help your client because SEO work should be considered a business secret. Professional bass fishermen have their secret baits, techniques, etc. SEO should really be considered a businesses secret sauce and nobody outside of the company has a need to know about it.
I know there are SEOs who like to brag that their clients are whatever or whatever, but I think that's foolish and not in the best interest of the client. It helps those SEOs attract clients to brag about who their clients are, but it only creates an opportunity to bring scrutiny on the site. While some may say they have nothing to hide, any SEO work done on a site is open to scrutiny and if the search engines feel the work gives an unfair advantage to the site they may take action to dampen the effectiveness of the work.