I also got a similar message last night.. but I just had a chat with their online customer care.. and got a soothing response...Check the screenshot..

Remson23:
Hello fellow Nairalanders, your Advice is needed and will be much appreciated. I got a message from Workforce that reads "2018 STERLING GRADUATE TRAINEE PROGRAMME-UPDATE, kindly check your inbox for a a link to complete your application". I have tried to get the link from my e-mail, both inbox and spam but no link was found and I was given a deadline for completion:12PM (noon), today 16/02/2018. If you got a similar message or you have anything to suggest please let me know your take. Thanks