Yes, you can add an acknowledgment header below the sources header. I use the link to the users profile name I want to thank, so people can find them. You can add whatever you want to thank them for, and as many people as you want involved in the profile. I add my own profile link at the end of the statement, so future visitors will know who added the acknowledgement if they want to contact me, and for future managers updating and maintaining the profile.
Example
==Acknowledgments==
#I would like to thank [[Doe-866| John Doe]] for their work on creating this profile, etc. [[Fife-1|Barney Fife]]