Technically, they were tied to Pioneer in the early days - The former Pioneer Indoor now known as Pi Percussion has been based in Romeoville since pretty much their inception. They were using Pioneer's Equipment and buses in the DCI off season to save costs. There was some overlap in staff initially with Adam Hill Serving as Director of the Indoor group and percussion caption head at Pioneer Drum Corps in the early years (2008-2010 maybe?).
Fast forward to this past WGI season, Pi Percussion (for good reason) drops the Pioneer name. Shortly after this Pioneer's DCI status is revoked but they still participate in the Southside Irish Parade with the help of alumni and a few students from a local Chicago school taught by a Pioneer alum (not Adam as listed above). There was some momentum captured through this effort which lasted through the summer in the form of a summer parade group (drumline). It seems they are hoping to have a home base in Milwaukee and continue to offer opportunities to the students who have been part of the summer group who are mainly from the Chicago area. This group may be be supported by Pioneer in some way shape or form but guessing that will only be equipment and transportation to shows.
A lot can happen in a few months though.