If its the new kit they will also have to announce the new sponsor. I'd be surprised if they do it that way
I'm going to change my prediction to a new contract for Alex Neil or Ross Stewart. Not one of the ones we are waiting to hear about.
Just can't see it being a signing (other than Roberts or Wright). Would be extremely rare to the point of "never happens" for the club to announce somebody that hasn't leaked in the hours leading up to it.
Whatever it is, the club clearly think fans will like it. otherwise they wouldn't give it this tease.