Plans for a new RoboCop movie started in 2016 at MGM. The hint comes from an interview Paul Verhoeven gave to Collider.com on September 2016 while promoting his latest movie Elle: (Click here for the original interview at Collider.com)
Here's the segment in which the RoboCop sequel is mentioned:
"It’s interesting, I just heard that they want to…when I did Robocop they immediately wanted to do a sequel the next year. This was Orion who went bankrupt, but that’s ok. So I was interested. In the United States they make sequels. I get it. So myself and Michael Miner started working on ideas. We were really thinking about it because I feel a sequel has to go further. I think one of the best sequels is Star Wars 2, probably. That is a sequel that’s good. Normally they aren’t good because it’s so difficult to find that inspiration. So I really wanted to take some time and develop something that deserved to exist and was different. But Orion didn’t want to wait, so they used other people. But I just heard that MGM was thinking of picking up the ideas that we were working on in ’87 (Laughs). I don’t know if they’ll do it, but they are talking about it."
Depending on how far ahead MGM is with the writting RoboCop fans might have an official announcement quicker than expected. So let's wait and see what happens