Nothing on the pilot service, but I would venture that if not this spring possibly the fall if people continue to return to commuting. In terms of the platform the idea I've heard floated is to build a platform inbound of the existing one at Walpole that serves both routes, but not sure if there is any real forward progress on it other than an idea. The current Walpole platform can't be made ADA compliant due to the historic station building.
The new spring/summer Commuter Rail schedule which will take effect on May 23rd is due to bring back regular service to Foxboro, as well as having the Franklin Line renamed to the Franklin/Foxboro Line.
https://www.keoliscs.com/news/mbta-comm ... ct-may-23/